Methinks

Enabling auto connect and wifi on bsnl routers

2009-12-10T04:07:00.000-08:00

In Pune, India for a vacation.

Switched to boradband from dial-up and was trying to work around the router BSNL provides with the connection. It says it supports wifi, and it does so decently.

BSNL engineer usually will create a dialer on your machine and charge you Rs. 600 to enable auto connect and "multi user" support. Multi user is nothing but allowing multiple machines (wired or wifi) to connect simultaneously to the router. Since it is dialer-based only 1 machine can dial and access Internet.

Enabling all this is like eating Goober Pie in Kramerbooks & Afterwords Cafe in DC (BTW, its amazing and a must try!). In short, very few changes are needed from the factory settings. Follow this to enable auto-connect and wifi on any of your BSNL dsl modem cum routers. Mine is DNA-A211-I.

1. Go to the default getway, most likely 192.168.1.1. If you are unable to get to it, feel free to reset the router to the factory setting by a small button at the back of the router.

2. Login using admin/admin, unless you have changed it. (You should!)

3. Go to "Advanced Setup" -> "WAN". Click on the "edit" button on the entry with values 0/35 for VPI/VCI and PPPoE for Protocol.

4. Select service category "UBR without PCR". Click next.

5. Select "PPP over Ethernet (PPPoE)" and Encapsulation Mode as "LLC/SNAP-BRIDGING". Click next.

6. Type username and password for your BSNL connection, "dataone" as service name and "AUTO" as Authentication Method. Check "Dial on Demand" and set 30 minutes (or whatever) as timeout. Check "Retry PPP password on authentication error" and "Bridge PPPoE Frames Between WAN and Local Ports (Default Enabled)". Click next.

7. Check "Enable WAN service". Click next, save and save/reboot.

The router should come up and have wifi enabled without having to provide BSNL password, ever.

Shiny new SuSE root file system for UML

2009-04-21T13:22:00.001-07:00

All I wanted was a minimal root fs with development tools (gcc, make, ...) for UML. This is especially important when, say, you want to test new file system tools which snapshot a directory, and this is only possible when the tools are available inside the root fs. There are many root fs elsewhere on the web, but none with development tools (and rightly so, since for most cases you won't need those).

So created a VM using VMware Workstation and bzip2'ed the '/' without /proc, /tmp, and /sys and manually created those directories outside of the VM. Also chopped down the unnecessary things on startup using chkconfig(8) and modified /etc/inittab to give 2 xterms on boot. Root password is 'guest'.

Have uploaded it on my homepage: http://people.cis.ksu.edu/~gud/tools/suse11.1-rootfs.bz2

Chiller room

2008-09-18T19:14:00.000-07:00

Saw this excellent Mira Nair debut movie Salaam Bombay!, and was wondering if the lead actor, 11 year old character called Chaipau (meaning tea and bread, in the movie hes working as a runner distributing tea for a tea stall) playing a street kid in Mumbai is really an actor. My suspicion was right, hes actually a street kid as like many other kids in this movie and no scene was shot in a studio.

I like such movies, non-fiction, real-life, albeit harsh more factual. Although I don't admire the intent of Mira Nair, as with this and noticeably in Monsoon Wedding, of showing only a bad picture of India. I am not contradicting myself, but there are things shown in her movies which are not needed and don't contribute to the story line. May be they are to be taken objectively or esthetically, or I'm missing the point. Nonetheless, Salaam Bombay! deserves all the accolades it has received.

(Chiller room is the term in the movie for a Government run center for development of children, which is shown as no better than a prison.)

As I Clean My Whiteboard...

2008-06-11T22:54:00.001-07:00

A friend of mine asked what am I gonna do on my 1st anniversary here at VMware. I jumped and said, "I'm gonna clean my whiteboard da!"

Theres a reason to it. Reason being it still contains tidbits of things dating back to June last year! Small things...things explained to me, things discussed with team-mates, things discussed with friends, and some things I noted down myself when working on projects..scribbled in blue, black, red and green. Some failed, some worked! As I wipe things off, I can recollect the time of the day it was written, the context and with whom. As if all done just yesterday!

Cleaned it be for the new things to fruition.

Clairvoyance is but fatal

2008-05-06T16:33:00.000-07:00

One of my friends asks in his blog:

"If you could foresee the next two minutes in your life, would you do things differently than what you otherwise do?"

Foreseeing something is, IMO, helpful iff the outcome is alterable. But is it even possible?

Saying "..foresee the next two minutes.." is ambiguous to say the least. It could mean 2 different things: 1) what I'm foreseeing is one possible outcome, OR, 2) it is _the_ outcome. In case of (2), unless you're in a gambling business or in a life-threatening situation, foreseeing is mostly useless (and even harmful!). We'II come back to this later.

As for the case (1), seeing a possible outcome assumes a sequence of, say 'n', events e_0(0), e_0(1), ..., e_0(n-1), within those 2 minutes, where e_i(x) is causally related to e_j(x-1); i < j <= x <= infinity, and 'n' belongs to [0, infinity]. e_0(n) happens after e_0(n-1) and is foreseen. Now this is just one possible sequence of events and there could be infinite sequences and for any value of 'n'. E.g., there could be another event sequence e_0(0), e_3(1), e_2(2), ..., e_999(n-1), e_7(n); in this case outcome is e_7(n). To simplify the calculations lets assume 'n' tends to infinity (in other words, substitute 'n' for infinity) and at most there could be 'n' events in any sequence. This also means that there are at most 'n' possible outcomes, e_j(n). Also this means that there are 'n!' events in all. All the possible outcomes are equally probable. Now the question is which outcome would you foresee? For the outcome you see depends on penultimate event and a series of events before that, which are causally related and directly related to the event that is going to happen next.

For example, consider a set of colored water guns. I'm to pick any one and shoot on a wall in front of me. The outcome is the color on the wall. If we apply the aforesaid theory to this, I can foresee a color on the wall. Now, in case (2), no matter what gun I pick, I'II end up spraying the color I forsaw. In case (1), chances are (since I did foresee) I choose the gun with the color that I forsaw. Now consider a case that the guns are correctly marked with the color they have. Now if I see a color, and I'm to change it, I'II cleverly pick the right gun and get the color I want on the wall. BUT, but the moot point is what I should've foresaw? The color that I cleverly didn't allow to appear on the wall, or the one that I did?

With this could we conclude that being able to change the future you saw kind of defeats the purpose of your clairvoyance?

Even if we assume we foresee an outcome that would happen if we don't try to alter it, our ability of altering the output greatly depends on the rate of change of events, time between e_i(x) and e_j(x+1); i < j <= x <= infinity. For example, such clairvoyance would help me if I'm a cricketer or a stock broker, but it'd hardly affect me if I'm a tea-leaf picker or a carpenter unless it is life-threatening. Same is true in case of (1), with an added danger that since we foresee an outcome, now no matter what we do, nothings going to change it. This has some obvious consequences, and more so if the clairvoyance vision is 2 years and not 2 minutes. We could think that all we can do is work towards the next outcome. But, wait..think. I'm a film maker and I foresee that my movie is going to be trashed, I can't completely stop working on this movie and take up next, it has to be done until trashed, but all I can do is...is nothing! I wouldn't find time to work on my next film, for the time has to be spent on things I already foresaw sometime back! And the output is unalterable! Things have to be done; and by me!

And with this could we conclude that foreseeing an unalterable future is but useless and prenotion of disappointment could do more harm than cheer of an oncoming success?

Animoto, pretty neat and ..

2008-05-06T00:42:00.000-07:00

Heard about this startup - Animoto. Its simple, it takes your pics, allows you to select a music track and compiles a video out of it and claims no 2 videos are alike. Neat, huh? The short videos (30 sec) are free but the longer ones are not. The shorter ones give a trailer kind of teaser feeling, and are actually great. How far are we to see such features in (*gulp*) Gimp and Picasa? Beyond a lame musical slide show, ftw :)

Just wanted to give it a whirl, uploaded a bunch of pics - random mostly and some from our recent quick Ghirardeli ice-cream late evening sprint. What came out is this - http://animoto.com/play/ni0VJUBru0DwstY7dplAgA

Long time no blog

2008-04-22T15:11:00.000-07:00

So parents depart after a good (short) half a years stay, and things change. I was preparing myself to be bored again, but it turns out, weekdays are (enjoyably) busy with work and every weekend continues to be equally fun-filled :) I now have more friends in the bay area than anywhere else, and the best thing is most of them are my old friends from Pune. Hiking, games and movies and coding make up my weekends, which otherwise was just coding :P

Blogging becomes scarce, out of pure ignorance, and having exciting things to do make it not so exciting ;) Plus twitter is there filling the need :)

the vegas & canyon

2008-03-02T11:41:00.000-08:00

Linux Storage & File System Workshop 2008

2008-02-29T10:36:00.000-08:00

LSF, is a premier meet for Linux file system folks. Being invite only, its the only concerned people that attend or rather allowed to attend this workshop. This is its third year and mine first. Only 60 odd people on the attendee list. Odd. Every big name you can think of in the Linux kernel community was there, notable exceptions of Linus and Alan Cox, but they aren't file system major anyway.

Heres the workshop program: http://www.usenix.org/event/lsf08/. And there wasn't any scope for any and every discussion not to be enlightening. Being a primary note taker, I was all the more attentive than usual. Good for me. Will hang off my notes here, as soon as I get them compiled in a readable way.

LSF was co-located with USENIX FAST 2008 and a BoF was arranged on the last day of the workshop which was open to both LSF and FAST attendees. I found it very interesting, especially since it allowed interaction between people from academia and Linux kernel maintainers. We discussed many issues surrounding file systems and storage apart from taking a overview of the discussions at workshop.

I enjoyed my presence at LSF a lot, more than just the day full of technical stuff, its about meeting and interacting with the small esoteric group of kernel developers, whom I revere since my school days. And now its easy for me to convince my mom that its ok if I work more, if akpm works 60 hours a week at his age :)

Why M$?

2008-02-02T17:52:00.000-08:00

Ok guys, pinch yourself if you want to, this is true. I'm thinking of joining a company in Redmond, called M$. I've already started preparing for the interviews. Megs tells me the most common question they ask, like any other company, is "why do you want to join M$?". I've come up with few possible answers. Here they are:

1. I'm a sinner, I think I deserve it.

2. I've heard lots bad things about your company, just want to check out if its really that bad.

3. I'm done with my life. I think suicide would be little too much.

4. Nothing else worked. Plans A-Y failed, you're my last resort.

5. I'm anti-social. Everyone hates me anyways.

Disclaimer: umm...aa..aaa..umm...a pinch of salt and a grain of humor.

Btw, feel free to suggest me more :)

Tip'Em

2008-02-01T22:48:00.000-08:00

This is one of those topics when I actually get to writing I feel why in the world I pitched such a story in the first place. But I'm glad to have all of my stories accepted. Its always more pleasure writing about things you're not familiar with than otherwise. And its always a pleasure writing in general, running around streets, meeting people, interviewing them and taking pictures. Its different than blogging in many ways.

I was researching about tipping trends and cultures worldwide for a small feature article. The insignificant looking thrifty money that we leave behind as a tip in restaurants surmounts to a multi-million dollar transaction in US alone. The waiter I interviewed at a Thai restaurant on Castro street, Mountain View, apparently makes more money than me and any of my friends. How's that? I inquired, but they have no new vacancies coming up anytime soon :)

Here's a study at Cornell about gratuities that I found both, useful and interesting - Beyond Gratitude and Gratuity.

Marathi Blog

2008-02-01T00:35:00.000-08:00

Don't want to clutter this blog with any non-English posts, hence a shiny new Marathi blog: http://aatichya.blogspot.com/

UFL Career Fair

2008-01-31T23:20:00.000-08:00

Reminds me of the project presentation days...talk and answer same things over and over.

The UFL career fair was nothing much different than KSU's, but I found UFL students taking career fairs more seriously. May be because UFL has more students or may be because career fairs at KSU are not much fruitful to computer science students. Although I did took first couple fairs at KSU seriously, later I didn't because I didn't have to, except for the free goodies. Its nice to be on the other side of the table though. And its always good to go back to school.

Weather in Gainesville, I found, is noticeably different...its more on the hotter side, but winters are pleasant. In all the places I've been, I can feel the difference in not only the weather, but in the air...Kansas, Boston, Palo alto, Seattle, Pune and Florida. It doesn't have to be true though, I don't have enough samplings.

The highlight of this trip, apart from a mouth watering "peshal" egg curry by megs, is that I had to give an impromptu presentation at the VMware info session. Thanks to some of the colleagues who chipped in.

Blog Face Lift

2008-01-17T22:54:00.000-08:00

Its been quite some time I was thinking of doing this..and finally couldn't resist myself any more cleaning up the clutter this blog had become. The swanky blog header comes from a mix and match in gimp. Wanted to depict a blend of deep thinking, an observer, and the conglomerate of thoughts in a color contrasting with the other colors used on the template...and what came out is this. Also now the font is much readable than before.

No option, you have to like it :)

Tujhse Naraz Nahi - Notes and Chords

2008-01-13T19:37:00.000-08:00

Great song. I rediscover it every time I listen to it, especially when sung by those talented competitors on the various singing shows. Listen to this kiddo... http://www.youtube.com/watch?v=s25r3YLPQOQ. Thanks Viv.

Album: Masoom (1983)
Song: Tujhse Naraz Nahi Zindagi (OST)
Singer: Anup Ghoshal
Music: R D Burman


A                           D
tujhase naaraaz nahi zindagi, hairaan hoon main
a   b  c# b c# b a b a f# e d e f# e f# f#

    D
o hairaan hoon main
e d d e f# e e e

A                          D
tere masoom   savalon se pareshaan hooN main
a b c# b c# b a  b  a f# e d e f# e f# f#

       A
o pareshaan hoon main
d d c# b c# b  a a a

A             A               Bm                 D
jeene ke liye socha hi nahi,     dard sambhalane honge
c# d  e  d c# c# d  e  d c# c# b b b  b  b  c# b f# a

A              A               Bm                 D
muskuraoon to  muskurane ke       karz utaarne honge
c# d  e  d c#  c# d  e  d c# c# b b b b b c# b f# a

A                A
muskuraoon kabhi to lagata hai
c# b c# b  b  b  c# d c# b b

E                     A
jaise hontonn pe karz rakhaa hai
g# b  g#   b     e    b   b   b

tujhase ...

Go Kats, Go State!

2008-01-11T17:24:00.000-08:00

Being in the default stream of Computer Science, its most likely that people like me end up spending most of their lives in bigger cities. And then the fond memoirs of a very small town like Manhattan, Kansas remains...where some lucky folks like me, for a short while, get to study, work, play, and make friends for life!! My k-state!

(Look mommy, I'm on TV! :))

http://www.stage6.com/user/d8485/video/2056154/Kansas-State-University---Go-Wild-Cats------

Kary's right, everyones making video these days :)

Twitter On!

2008-01-10T17:25:00.000-08:00

Enough said and heard about it. They call it "micro-blogging." Nothing fancy about it, just another buzzword. With it you can blog one liners..like where you are, what you are doing and feeling. Good thing about it is you can feed it right on your blog, like I have it with "What am I up to?" on the left. Also there are few firefox extensions as well that allow you twitt-ing from firefox. Twitter is ad-free as of now...or I'II be the first to dump it. Lets see how far it goes.

PARC forum talk was very interesting. More on today's topic here: http://www.hpl.hp.com/research/idl.

Kalifornicated...forever!

2008-01-05T13:31:00.000-08:00

Kary says it all, both in words and in this picture compilation. Need I say more? Thanks Kary! and kudos to everyone! :D Feels its a lifelong vacation now :)

http://www.youtube.com/watch?v=O_fvHT6V4So

End of the Year

2007-12-31T22:34:00.000-08:00

Since last year, its the year ends that are most exciting and fun-filled part of the year. Its like making up for all the joy for the entire year towards the end of it....all cramped, within a span of a month or so. Last year I was back at home...and this year again with my parents and friends. 17 mile drive, muir woods, stinson beach, santa cruz, mystery spot, napa valley, sfo, tanferd (:)), berkeley, kayaking, canoing and much more. The vacations been tiring, really...busy schedules, rest is highly needed it seems after this long leisurely break :D

Back to the card game (badaam saat with two card decks!), while the Robert Mondavi desert wine from Napa awaits to be opened at the thoka of 12!

(someday will update this post with pics.)

2007-12-30T08:08:00.000-08:00

On thickness of the equator

2007-12-19T14:24:00.000-08:00

Multiple Dimensions - Quicktime | RealMedia

I don't completely outcast the possibility that there could be 11 or more than 4 dimensions in this universe (I see these dimensions more as properties, saying these as spatial dimensions is what throws me off...could be true, but this is so unsettling!), but saying that the ants circling the wires supporting the light post as moving in 4th spatial dimension is utterly insane. However may the ants move, clockwise or anti-clockwise, they still are in 3 spatial dimensions - they can precisely be located using just 3 dimensions at any given time! And how can this analogy be used to say that the space-time fabric could well be rounded and so forth and serve means for additional dimensions? This is like saying equator has a thickness!

As I was saying to one of friends recently, I wish I could be alive 100 years from now to get the answers to this ultimate quest, but may be I'd be making exact same wish then.

Plenty of food (not junk) for our minuscule brains:
- Elegant universe
- Imagining the 10th dimension

Yet Another Bubble Burst

2007-12-13T21:04:00.000-08:00

Very good parody! I originally watched it on YouTube, but apparently its being pulled on and off couple times because of petty copyright issues. Heres the Yahoo copy of it.

Guy Kawasaki's talk at PARC forum today was worth attending. He is good at putting forth stuff and marketing in general. The talk was much related to the Web 2.0 and his own new venture truemors.com. Not too impressed with this new venture, but with his way of presentation and his experience with the venture.

Oh and yes! Its been an year for those magic moments! Me going back home!! The month-long countdown and the situation climaxed by the algorithms exam...added to the fun, excitement, and happiness!

The New Age of Entertainment, Part II

2007-11-25T15:53:00.000-08:00

Ok, well, tv-links.co.uk has been raided by FACT. tv-links was a link aggregator that just deep-linked movie and TV shows from popular video sites, like Youtube, Veoh, Daily Motion, Stage6 and such.

When I look closely to what exactly is illegal in case of tv-links, it perplexes me a bit. Surely freedom-of-speech is legal, so is deep linking (had it been illegal, entire Internet would be too). IMO, only thing illegal in this context is facilitating the distribution of copyrighted content. But is pointing to copyrighted content with a proper disclaimer illegal? Are disclaimers enough for leechers like tv-links? Would it be illegal if I say, "go find some drugs in that bush, but wait..I'm not responsible for the consequences." Inappropriate? Yes. Illegal? May be.

But, video sites are untouched and arguably rightly so, the videos are user generated and the sites provide means to take the content down if the material is known to be copyright protected. But then how far are sites like piratebay, isohunt legal? They facilitate distribution of copyrighted content as well, and that too for downloading unlike tv-links. Oh, and don't forget sopcast and the whole list of p2p players (PPLive, CoolStreaming).

Agencies like FACT should've been smart. Certainly it takes lot more to upload something, find, link and index it than reporting or removing it. Sites such as tv-links tries hard to keep the links updated, so why not just exploit their knowledge and make it even harder for them by just reporting / removing stuff they update? Think feeds, this can even be automated!

Although, tv-links is gone for now, it only takes some right keywords and a decent search engine to get to everything you wanted. Perhaps "tv-links mirrors" ?

Younger, Nerdier Founders

2007-10-25T17:20:00.000-07:00

I smirk as I read this Paul Graham's essay on the future of web startups. He writes:

...founders can start them [startups] younger, when it's rational to take more risk, and can start more startups total in their careers...

This reminded me of my first business plan which I had prepared just after my higher secondary schooling, which I tried selling to any and all VCs and angel investors around the globe..from Fidelity, Garage to my dad and brother-in-law. It was a complete plan detailing the revenue model, parties involved, the split up of the fund requested, rough estimates on break-even point and much more. I had even registered a domain name, parked at Net4Domains! But, as you know now, the plan was not funded. But I had so worked on it!! It was so much fun :) If theres anytime I want to go back in my life..its this time. It was so much fun exploring and testing the waters..it was during these times I started writing for foreign publications, and doing crazy things like thinking of starting a startup!

Well, I don't think its too late to revisit the plan and rewrite it, I might get lucky this time :) Or may be seed fund would be enough this time. Of course, this time it would be much more fun and that too serious fun! :)

Swades

2007-10-24T22:53:00.000-07:00

Wow! Unfortunately I never completed movie Swades until today, that way I have a pretty long backlog of movies...I'm not prompt enough when it comes to watching movies.

As I mentioned in one of my previous blog, I'm spending some quality time of my life. I wish everyone gets to spend such moments. Early this month, my parents took _the_ flight from BOM to JFK, it was a long journey, very long, some not-so-pleasant, some almost breath-taking moments, an arduous journey..with pretty moments in between. I'm glad they are here...finally. They are glad they are here. While flying to SOSP last week I took Alaska Air. They are celebrating their 75th anniversary. One of their posters really touched me..it said "No matter where we go, we always remember where we came from." It showed a state-of-the-art boeing plane having a shadow of an age-old Stinson aircraft. I strongly and religiously believe in this. No matter what happens, never forget where we were, and what hardships we've been through to get here. Never forget the pretty faces on the way, could be your parents, friends, relatives, teachers, your own aspirations and ambitions, the ones who cheered you and pumped you to keep going. After all, I think, thats what humanity is, thats what is life. Look over the world, challenge and conquer it, but never foget the shoulders on which you are standing. In one of those stories that my mom reads during some devi puja on every thursday of that month..the gist of the story is (in marathi) "utu naye matu naye," that translates to when ultimately you get what you always wanted...never forget the way on which you came and the entities that supported you on the way...in other modern marathi words..."kadhihi maaju naye."

The theme of Swades is somewhat inline with this. The plight of the people shown is not mere artificial but an artifact of the rudimentary beliefs and socio-economic thinking. Mohan sees it all..his heart sinks heavily, Mohan goes back to his roots, he understands where he should be and what he should be doing.

One day, I will be Mohan!

SOSP 2007 Notes

2007-10-19T12:27:00.000-07:00

All papers and the program can be found here: http://www.sosp2007.org/program.html

Listed here are my notes of the talks I found interesting:

Day 1

MashupOS - Microsoft Research

Inline modules in HTML currently exhibit all-or-nothing behavior. They can either run with no interaction with the other components of the page (iframe) or run with the same privilege as that of the page (script).
Introduce tags for allowing integration of unauthorized components from third-parties. This allows aandboxing external scripts running within a browser.
Used for multiple-principle sites pooling in third-party principles and integarting as one.

AjaxScope - Microsoft Research

For examining ajax execution remotely.
Uses a ajax proxy between the server and the clients to insert the instrumentation to debug, test and optimize the ajax code.
Injects javascript within the applications on the fly, to capture logs.
Logs are sent back for inspection.
No need to modify the client side code or browser.

Automatic Partitioning (Swift) - Cornell (Best Paper Award)

Javascript-like programming language for auto-splitting client and server side code.
Compiler decides which code should run where (client or server) based on security minimizing messages flow.
Handles security and integrity using annotations.

TxLinux - UTAustin

Transactional memory to be reality in Sun's new "Rock" processor.
Locks are difficult to implement and use in the code. Makes code complex.
Initial implementation to use transactions in Linux kernel. Not-so-easy to do due to legacy code and transactional-unfriendly code, especially involving I/O.
Implemented co-operative transactions, which dynamically choose between spinlocks and transactions depending upon conflicts and I/Os.
Easy to implement than complete lock to transaction conversion.
Transactions are made scheduling aware to eliminate priority inversion completely.

MUVI - UIUC, MIT

Variables are corelated, they relate to one or more variables.
Idea is to leverage the relation of variables statically and identify possible bugs.
Corelations are inferred by variable placement and distance between the usage of the variables.
These corelations and the frequency of variables occurring in groups is calculated, which is used to detect if the developer has forgot to update or initialize a variable.
Found real bugs in Mozilla.

Day 2

iComment - UIUC

Comments in the code could get stale or incorrect over time. They are often used to specify assumptions made by the piece of the code.
Idea is to leverage the developer's assumptions for verifying the correctness of the program.
Uses NLP, statistics and data-mining to derive a set of frequently-used words for detailing certain things, like e.g. that a function should be called only with the locks held.
Uses the decision tree to verify if other parts of the code ammend to the comments.
Notifies for a possible bug in the code or invalid comments.
No need to retrain or remake the decision tree across softwares since developers often use common words to siginify things. But can remake for less false-positives.

Sinfonia - HP Labs (Best Paper Award)

Every distributed systems involves a complex message-passing protocol taking into account failures and concurrency issues.
Idea is to have a framework which will deal with message passing and provide availability and concurrency guarantees.
Sinfonia provides minitransactions as a primitive for building a data-centric message passing systems like cluster file systems.
It takes care of load-balancing, fault-tolerence, coherency and scalability.

Dynamo - Amazon

Amazon needs key-value storage solutions, it built it for themselves with 99.9% availability.
It did not detail about how it measured 99.9% availability, but it uses distributed hash-tables with consistent hashing and versioning.

Integrating Concurrency Control and Energy Management in Device Drivers - Stanford

A solution of efficient energy use in sensor networks. Implemented in TinyOS.
Uses a power manager which drivers talk to for device-specific operations. The power manager handles the powering-off and powering-on of the device depending upon the requests.
Amortizes the cost of powering-on and powering-off by trying to do it less frequently.
Might as well be used for mobiles OSs and even generic OSs.

Day 3

DejaView - Columbia University

Personal desktop experience recorder - fast and transaparent
Virtual display driver to record the display on disk.
Uses accessibility features of the OS and applications to record the keys and clicks, which also provide meta info about the text (application, menu text, focus)
File system snapshotting for recording fs state.
Allows browsing, replaying and restoring application states.
Does not handle network connections.

I/O Shepherding - Wisconsin Madison

File systems are not flexible enough to mould to differnt deployments (servers, desktop).
Different reliability policies are helpful in different deployments.
I/O shepherd allows specifying reliabity policies by the file system developers and takes care of enforcing those.
All the I/O goes through the shepherd, it can do more I/O or modify the I/O as per the policies set for that I/O.
Allows specifying fault-detection and recovery policies.

Generalized File System Dependencies - UCLA

Writing individual policies, like journaling and soft-updates, for individual file systems is difficult and cumbersome.
Idea is to be able to write such policies in a fs-agnostic way.
Proposal is to handle each change going to the disk as patches. Each patch is a change going to a block of the disk.
Patches are linked together as per the enforced dependencies (certain writes may be needed to happen before some other write).
Policies then are implemented only dealing with patches.
Patches are merged and rendered unimportant when possible.
Allows easily write the policies and features and which can be applicable of any file system.

SOSP 2007 - Stevenson, WA

2007-10-17T20:47:00.000-07:00

Its been a while. Spending some good time overall. Not as productive as I'd like, but ya, quality time :)

VMware (also) sponsored 21st SOSP this year. SOSP is a biennial ACM conference on Operating System Principles. Undoutably its one of the presitigious conference in operating systems area along with USENIX OSDI. I was fortunate enough to attend both of these, once as USENIX student scholar and now SOSP with VMware.

SOSP, though OS-focused,I found very inclusive to accept papers on programming languages not directly related to OS. The talks were excellent and so were the papers. Most notable were TxLinux, I/O Shepherding, Featherstitch, Amazon's Dynamo, and HP Lab's Sinfonia.

Got some great research feeds, revived my aspirations of PhD, and of course met some really sharp people.

SOSP is known for the locations where it is held. This year it was at Stevenson, Washington, about 40 minute north east of Portland. Very small town with nothing much in it. But fall was at its best and conference host hotel was at an excellent location. Very well picked indeed. SOSP brought some good tourist business around Stevenson overflowing the hotels in the region. For the first night I reached Stevenson at around 11 in the night and the place on the banks of Columbia river with railway line passing right next to the lodge and the place was without phones and TV. I felt adventurous. Those were individual rooms spread across a small area. The dim lights and the red-indian interiors with patio and wooden roofs and floors reminded me of those canibal movies :| Fortunately I was able to move to the hotel where the conference was hosted for the remaining nights, and it was much prettier. The view from the lobby of the hotel was stunningly awesome!

I'm yet to digest the info gathered. Might post here my notes as well.

Hope to be able to go to future SOSPs as well :)

Cursor on Firefox?

2007-09-12T19:06:00.000-07:00

Press F7! Its a feature and an annoying one until you know about it. Its called "caret browsing." Well its been around for a long time..but I noticed it until recently, when I changed my keyboard for mercy of my hands and started pressing all the wrong keys! :)

More here: http://en.wikipedia.org/wiki/Caret_navigation

Cheers!

2007-08-14T12:30:00.000-07:00

Past 8 days have been pretty eventful - couple brand new US tourist visas, couple brand new Honda Accords, and a brand new IPO!! VMware (VMW) goes public today at NYSE, making (or in the making of) hundreds millionaire :) Good company to grow with! And me and my friend (minua) got a steal deal on Honda Accord!

Hail VMW!

A Busy Weekend (pun ;))

2007-08-06T12:24:00.000-07:00

Yanda Kartavya Aahe
Aga Bai Arechya
Pak Pak Pakaak
Kai Dyacha Bola
Shubha Mangal Savadhaan

(in no particular order)

Today:
Dombivli Fast

Theres nothing as entertaining as Marathi movies :D

Kase Sartil Saye - Notes and Chords

2007-08-02T23:01:00.000-07:00

Song mainly in Bb (A#). Other stanzas are same with slight variation within the Bb octave. I'm not too confident about the third chord, I've used Ab, I could be wrong.

To my saye ;)

----

Song: Kase Sartil Saye (OST)
Album: Divas Ase Ki (marathi)
Singer: Salil Kulkarni

Suffix '1'- indicates note from next octave and '0' from previous.


Bb 
kase sartil sai
f a# a c1 a# a#

Bb (actually Ab cal also go here..but its Bb in OST)
mazya vina dis tujhe
f  g#   g   f   d#

Eb                Ab     Bb
sartana ani saang saltil na
d#   g   f  d# d  c  d#  d

Bb
gulabachi phula dona
a#0   c   d  d# d c

Bb (can also try Ab)
roj ratri dolyavara
c   d     d# f d# d

Bb
musu musu paani sang
d      d# f a#  a c1

Bb                   Ab     Bb
bhartil naa..........bhartil naa
a#  a#  g# g f d# d  c   d#   d


Stanza:

Bb                    Bb
Pavsachya dhara dhara mojatana disa sara
a#    d   c   a#   g# g#  a#  a# a#  g#
(remember the notes are elongated)

Bb                   Eb
rite rite mana tujhe ure
g#  a# g# g    f     f g

Bb                   Bb
otha bhara hase hase oratun vede pise
a#   d   c   a#   g# g#  a#  a# a#  g#

Bb                 Bb
khol khol kona aat zure
g#   a#   g#   g   f a#

Bb
aata jara aali mili
f    a#   b   g  f

Ab
tujhi majhi yatha nili
f     g#    g  f  d#

Eb                Ab      Bb
sosatana sukhavun hashila na
d# g f   d#  d    c  d#   d

gulabachi phula dona
roj ratri dolyavara
musu musu paani sang
bhartil naa..........bhartil naa

Two...and still counting.

2007-08-01T22:34:00.000-07:00

Its been exactly two years now, since I came to US. They say if you count something it decreases in number. I wish thats true. Things have changed rapidly over the last year. Going back home in December was a heveanly relief. Something I'm again looking forward to and that too more desperately.

But, some hearts have broken - my H1 is approved. My hopes of going back home for couple months have been crushed :(

Now I'm at my third city in US - Manhattan, KS -> Boston -> Palo Alto. And every place had something to offer...and its hard to pick one out of three.

Recently I'm finding myself doing just two things - coding and playing music. Coding has always been my lunch and dinner, so thats not surprising. But music is taking my more than usual time..and its a rewarding pleasure :) Voila! (read violin ;)) I bought a cheap violin! I had initially thought I'd take lessons, but as I started playing it..I dropped the plans and now am just learning on my own. Knowing guitar kinda helps in learning violin. Violin is more intrigue than any instruments like guitar. You have to tune Violin every time you play it. You have to apply rosin to the bow which is made of horse hair before you can generate any sound out of the bow. Your hand aches when you hold the violin long enough. But it really has a soothing tone.

I hope I won't have such year counting posts often.

Research. Mainline or not.

2007-07-27T13:25:00.000-07:00

Recent examples of Reiser4, and RSDL/SD make it difficult to convince someone that they should work in an area to contribute towards Linux kernel and it will be appreciated. Work, IMHO, should be done for the sake of research and not with a goal of getting it included into mainline / upstream. If someone appreciates it or not really depends on whom you ask. Getting the work included in the mainline is no indication that it is of no importance, it just depicts that enterprise world is not benefiting much from that piece of code.

Ratatouille and the Baseball game

2007-07-14T15:43:00.000-07:00

Last week my company gave away tickets to a matinee show and we bunked the afternoon's work for the Ratatouille show. Its really a cute movie. In general, I tend to like animated movies a lot. The whole idea of this rat aspiring to become a chef is so unique and crazy. They really did put it up very well.

And yesterday I sneaked into a baseball game between SF Giants and LA Dodgers at AT&T Park in SFO. Again, VMware arranged this for all the interns and their mentors. I could go because of a spare ticket by our team member. Although, TNT has beaten it to death, I'd like to add that I didn't really enjoyed it as much as I would've enjoyed for a cricket match. I feel these games are so very commercialized that watching a game is reduced to merely hanging out with friends and eating garlic fries. But the location of the stadium was awesome, the bay was in the background with some what huge ships and was surrounded by bridges. A nice experience though :)

Tum Pukar Lo - Notes chords

2007-07-11T00:04:00.000-07:00

Awesome classic song, one of my very favorites. This song sounds really good on mouth organ than on keyboard. I'm giving it a try. Do rectify if anything is wrong - after all, source is with you :)


Song: Tum Pukar Lo
Film: Khamoshi
Singer: Hemant Kumar
Notes: Western.
Chords above in caps; lead below in small letters

Suffix '1'- indicates next note from next octave and '0' from previous.


M0 (prelude - just lead, no chords):

F F F F G  C1 Bb Bb Bb Bb G

Hmmm hmmm hmm...
D B   B A B A B A G A  F A G  D F E  C E D

(repeat first line)
F F F F G  C1 Bb Bb Bb Bb G

M1:

G     F
Tummm mm mm mm
d  b  a  g  f 

  G
Pukar Lo
d g g  g

   F G       F
Tumhara Intazaar Hain
g c1 b  a g g a a a

G     F
Tummm mm mm mm
d  b  a  g  f 

  G
Pukar Lo
d g g  g

G                  F
Khaab Chun Rahi Hain Raat
g  g   g   g  g g f e  d 

G
Bekaraar Hain
d d  g g  g

   F   G    F   G
Tumhaaaraaa aaa aaa Intazaar Hain
g  c1  b    a   g    d d g  g g 

G     F
Tummm mm mm mm
d  b  a  g  f 

  G
Pukar Lo
d g g  g


Stanza:


G          F
Hoton pe liye hue
b  b  b  b a  b c1

              G
Dil ki baat   hum
b   a  c1 c1  b

                  F 
Jaagteee raheenge Auuur
d1 d1 d1 d1 d1 d1 c1 b a

            G
Kitni raat  hum
a a   c1 c1 b a g

G
Muktasar si bat hain
g  g  g  g  g g f e d 

G
Tumse pyaar hain
d   d g  g   g

   F   G    F   G
Tumhaaaraaa aaa aaa Intazaar Hain
g  c1  b    a   g    d d g  g g

Things so small ...

2007-07-04T21:22:00.000-07:00

- finally had my haircut after a month long delay

- finally my debit card arrived :D Now I can call home "freely"!!

- found a short way to bike to office saving me a mile! Now its roughly 1.2 miles now :) (1.2! isn't that awesome?) This way goes through a park and a hospital. Only for day-time use though, no lights at nights; but anyways going back home from office, which is 2.2 miles, is mostly a slope :)

- learned how to make an expresso with steam and without burning hands ;)

- got my first bug fixed!

la fete du Canada!

2007-07-01T11:32:00.000-07:00

Its turning out to be my best conference so far. I like techie talks, and in a city with a French touch celebrating its 150th anniversary as capital of the nation..its amazing!

My BoFS at OLS did go well..with more attendance than I expected, even though it was friday night. I had already started feeling feverish, may be due to insufficient sleep and wandering in cold weather because of some credit card problem in the Hotel I'm staying (I lost my only debit card I had and the one I applied for hasn't arrived yet). The day after my talk, yesterday, I decided to take half day off..woke up late and went to wander around only to see that Rideau Canal is celebrating its 175th aniversary and the announcement of Rideau Canal as a UNESCO World Heritage Site! The area around canal was transformed into early 19th century, with troops, bands, blacksmiths, ladies and men with the periodic attires.

After the transformed period, I came back to cutting edge stuff of 21st century with James Bottomley giving a keynote address concluding OLS on "Evolution and Diversity: The Meaning of Freedom and Openness in Linux." I have two cents in response to his talk, but later.

The talk was followed by party at one of the local pubs. With almost in ready-to-fall condition due to body-ache, I just showed up for a while and came straight to the hotel.

Today is the day! The Canada Day. There are events going on throughout the nation, and especially in Ottawa for its 150th anniversary as Canada's capital. The celebration party at the Parliament Hill in Ottawa goes with a tagline "149 years in making." Dressed in red troops on horses, band mainly of bagpipers wearing skirts and cavaliers in long fur cap with its belt going tightly across the jaw just below the lower lip performed in the Parliament Hill early this morning. To my very surprise, the stage performace started with a Punjabi song, fused by the European and Mujra (derived from Kathak) dancers! Probably the most spectacular was the SkyHawk planes display from Canadian Air Force saluting the Parliament heads and the National anthem. Was truly splendid!! I guess this is best time to be in Canada, and Ottawa!

Now, after a grueling 5 hour stand in a feverish condition, am relaxing in my room. Although I eagerly await the fireworks late evening today.

A toutes et a tous, bonne fete du Canada! (copied ;))

Ottawa Linux Symposium, Day I

2007-06-27T21:19:00.001-07:00

My first impression of Ottawa was..royally splendid! Literally. I haven't seen any US city downtown as royal as Ottawa. Is it mandatory here to have country flag (or some such) on every building? I miss my digicam. The glittering night view of the city of Ottawa from 23rd floor of my hotel room shows the Ottawa river and some boats. I like cities based alongside a river.

The talks so far were OK, there are roughly 4 parallel sessions for 4 full days. This specific conference is mainly for seeing people face to face and knowing whom you're working with. People meet here with whom they work almost 24/7 but never see them. This is there chance to talk to each other in person. This is an upside of working in open source...you know lot of people and lot of people know you. Not by the face, by your name. Work speaks. OLS is, unsurprisingly, different from traditional technical conferences. Emphasis here is more on practical implications and talks have more of implementation details unlike other technical conferences. Companies fund such conference becauase they want to be associated with Linux, want to spread the word that they do Linux. Some others do to build open source communities around projects of their interest.

Overall the talks are good. Its like those redhat days..hackers with pony tails talking hardcore kernel :) And its good to meet and know people. Source has power..to motivate and innovate. I'm with open source.

Student, I am

2007-06-24T14:26:00.001-07:00

Laziness is the appropriate word for reasoning about my sporadic blogging activity. Although lot of shifting, moving and relocating could also justify why I didn't blog for the past month.

So, the OPT finally arrived and I headed to California as soon as I could. It was for Ramu and TNT, that I got a headstart in the bay area. Almost no weekend is idle since I came here.

Within couple days I ended up renting a 10x10 room in a 4-bed house. The owner James (kind hearted agedly American) lives in an RV and I guess makes his living by renting all his 4 bedrooms. The house is almost a garage-turned-into-house, with all the things James collected throughout his lifetime - books on cuisines, travel guides to as far as Thailand, antique knives, cryptic dated paintings and wall-hangings, couple couches, plenty cupboards, couple more couches, plenty lamps, couple VCRs, DVD / cassette players, a huge (almost 40 inch) TV with a barely-working remote. The house is unduly-furnished. Kitchen is well equipped..with every possible thing you'd need..and clean. Alongside is a nice eating area with a table with a window and a lamp..and a fat book on tours in US. Plus a backyard with a table, BBQ and lot of wood. All this is yours for less than 700 bucks a month. Mind you, you're right in the heart of Palo Alto and CA in general is expensive.

I'm yet to use kitchen and laundry. Only two things I do in my newly rented place is shower and sleep. Company I've taken up job with, VMware, is just 2.2 miles from this place and biking makes sense..in fact, its perfect in the CA weather. The company shifted to new locations within Palo Alto and the new place is right across the historic place - PARC, where many things were invented including laser printing, GUI, OO programming, and Ethernet. This place truly is a valley and after being in Kansas for a while its nice to see mountains around. Its a pleasant bike ride to and from the office.

I'm now loving this place..there are huge number of things to do and go. Last Sunday we drove to Lake Tahoe. Although its more scenic in winters, summers do no harm to the beauty of the place. Its splendid...especially the drive.

On the work side, its non-opensourse file systems for some time. But, efforts are on the way for stuff I'm doing be opensourced :). Its a nice place to be..and almost all the colleagues are from top 10 schools in the country. So some sharp minds doing some bleeding edge stuff.

Is work life supposed to be different? I don't think so..I'm still a student and will forever be!

And finally I also got my visa to Canada yesterday. I'm now definitely going to OLS :). I'II be hosting a Birds-of-a-feather session on my thesis topic - chunkfs. Will surely blog about it. See you at OLS!

Blogger 2

2007-06-01T17:25:00.001-07:00

100th post, new version, new look. Good enough to postpone my decision to migrate to some other blog site :)

Ext2 Number of Data Blocks

2007-05-31T20:11:00.000-07:00

In Ext2, an FFS derivative, not all blocks associated with a file contains data. Some are used for storing pointers to the data blocks, called as indirect, double and triple indirect blocks. Finding actual number of data blocks from a given number of blocks associated with an inode in O(1) time I thought, wouldn't be that time-consuming. I was wrong. After spending almost entire evening few weeks ago trying to code it, today again I had to fix it for it wasn't correct! This is the fixed version, as of today:

/*
 * Do not count the {,double,triple} indirect blocks.
 * While calculating ceiling, the result is subtracted because
 * it is to be counted as extra number of blocks.
 *
 * [FIXME] This code hates sparse files, and the math is ugly
 */
blkcnt_t block_count(struct inode *inode)
{
        blkcnt_t blks, dind, tind, diff = 0, level, rem;
        int addrs_per_block = (inode->i_sb->s_blocksize / sizeof(blkcnt_t));

        /* see DQUOT_ALLOC_SPACE_NODIRTY and inode_add_bytes */
        blks = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);

        /* if has an indirect block */
        if (blks > EXT2_IND_BLOCK)
                diff++;

        dind = EXT2_IND_BLOCK + addrs_per_block;
        if (blks >= dind) {
                diff++;         /* the double indirect block */

                if ((blks - dind - diff) < (addrs_per_block * addrs_per_block + addrs_per_block)) {
                        rem = (blks - dind - diff) / addrs_per_block;
                        /* calculate ceiling */
                        if ((blks - dind - diff - rem) > addrs_per_block * rem)
                                rem++;
                        diff += rem;                    /* indirects */
                }
                else
                        diff += addrs_per_block;        /* indirects */
        }

        tind = dind + (addrs_per_block * addrs_per_block);
        if (blks >= tind + diff) {
                diff++;         /* the triple indirect block */

                /* calculate, number of double indirect blocks */
                level = (blks - tind - diff) / (addrs_per_block * addrs_per_block);
                diff += level * addrs_per_block;        /* indirects */
                /* calculate ceiling, here 'rem' stores remaining blocks */
                rem = blks - tind - diff - level - (addrs_per_block * addrs_per_block * level);
                if (rem > 0) {
                        level++;
                        rem--;
                }

                diff += level;          /* double indirects */

                /* for remaining blocks, calculate number of indirect blocks used */
                if (rem > 0) {
                        level = rem / addrs_per_block;
                        if ((rem - level) > level * addrs_per_block)
                                level++;
                        diff += level;          /* indirects */
                }
        }

        return blks - diff;
}

Userspace version. When I'II take technical interview next, this will be one of the questions :)

ChunkFS Git Repositories

2007-05-27T11:16:00.000-07:00

I'm moving ChunkFS git repos from cislinux.cis.ksu.edu to kernel.org, which will contain the latest developmental code for ChunkFS.

git://git.kernel.org/pub/scm/linux/kernel/git/gud/chunkfs.git
git://git.kernel.org/pub/scm/linux/kernel/git/gud/chunkfs-tools.git
git://git.kernel.org/pub/scm/linux/kernel/git/gud/fuse-chunkfs.git

Also, fuse-ext2:
git://git.kernel.org/pub/scm/linux/kernel/git/gud/fuse-ext2.git

The repos are web-browsable using a nice Gitweb interface:

http://git.kernel.org/?p=linux/kernel/git/gud/chunkfs.git;a=summary
http://git.kernel.org/?p=linux/kernel/git/gud/chunkfs-tools.git;a=summary
http://git.kernel.org/?p=linux/kernel/git/gud/fuse-chunkfs.git;a=summary
http://git.kernel.org/?p=linux/kernel/git/gud/fuse-ext2.git;a=summary

Rebasing Git Branches

2007-05-26T14:37:00.000-07:00

While trying to rebase my git repos based on 2.6.18 to the latest kernel, I faced some problems. Initially I had started with 2.6.18, converted it into a brand new git repo locally and started doing my changes. Now rebasing to the new kernel is difficult with the default options available in git. Here, a tool called Stacked git comes in handy.

I'm not too conversant with either of the tools, so with some help from IRC and with some experimentation I was able to do it with the following sequence of commands:

# stg init
# stg uncommit -n (this saves the commits as individual patches in .git/patches/<branch-name>/patches/ directory)
# git remote add linus git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
# fetch linus
# git checkout -b mybranch linus/master (where 'master' is the current branch to which changes have been made, 'mybranch' is the new branch that will be created)
# git reset --hard v2.6.21 (to have a known good version of upstream)
# stg init (again)

Finally for every individual patch created in .git/patches/<branch-name>/patches/ directory with the step above, do:

# stg pick <patchname>@master ('patchname' is the name of patch)

A list of patches can be obtained with

# stg series -b master

The New Age of Entertainment. Part I

2007-05-19T14:02:00.000-07:00

While I await for my OPT to arrive before I start my full-time job, I have some time to kill apart from the projects and the regular stuff I've been doing.

Lately its been lot of movie and show watching. And its amazing to know today how satisfied an entertainment consumers can be. You just need a computer with an Internet connection and you are all set. There are plenty and plenty (and plenty) of sites offering free movies, tv shows and almost everything you'd want to watch. The major benefits of viewing media online are not only it allows flexibility in the time you spend watching, but it also offers you huge variety of entertainment options. That too with a viewable quality and most importantly without any commercials. Its like a dream come true for an entertainment consumer. And can certainly be said as a golden era for entertainment consumer. Today you can watch almost anything you demand, from the current tv-shows, to very (very) latest movies (shrek 3 released yesterday, now available on couple sites for free viewing), to any old movie or any old tv show that you watched in your childhood. Its just amazing. Whats more amusing is that many stuff online comes in a very good quality audio and video, even in divx quality on many sites.

The sites are plenty:
www.tv-links.co.uk
www.bollydhoom.com
www.moviewalah.com
www.alluc.org
www.movie6.net
www.peekvid.com
www.quicksilverscreen.com

Whats booming all this? Wheres are the copyright laws? Is DRM dead already? (I wouldn't disagree that DRM won't work at all..but I have a post due on that.)

The main reason for proliferation of movies and tv shows are the gateways or "leecher" sites that do not actually host anything but just act as link-aggregators providing links to the content available on different servers. Its illegal in US, for example, to host any copyrighted content for unsolicited public downloads, so many leechers link content from servers outside US, like ouou.com in China. But leechers promote copyright violations and are thus illegal anyway. But more they are suppressed, more they sprung up..more in number and more powerfully. Leechers are small sites, (just may be a desktop machine hosting the site, and thats it) and many in number. If one gateway is shutdown couple more sprung up. And its a never ending benefit for the consumers. For the media companies, its more compelling to sue high profiting big-company-backed movie sites like youtube, that such leechers. But these aggregators are certainly creating a shift in the way the consumer consumes his dose of entertainment.

Consumer who have experienced this new age of online media, is becoming habitual about how he wants his entertainment dish to be served. Now he wants it when he demands it, good quality, ads-free, and possibly free (as in free beer). And he will likely to get it from now on. Music, media companies will have to work around to sort out things related to the digital media, and are already in process by legalizing downloads for a small fee.

PGP Public Key B24B7BA4 Revoked

2007-05-18T16:20:00.001-07:00

I don't know how, I was not able to decipher an encrypted email using my B24B7BA4 key for my ksu email address. Ultimately after trying hard, I had to give up and revoke the key. Below is the revocation certificate.

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.2 (GNU/Linux)
Comment: A revocation certificate should follow

iFQEIBECABQFAkUC6bUNHQBiYWNrdXAgY29weQAKCRBfZ6RPskt7pBPMAKCQYyW2
t0pxGpsdltxqtp2nVZfmCwCgmwddV8CYArfb7iKc4qu1b85id+w=
=dxo2
-----END PGP PUBLIC KEY BLOCK-----

My new PGP public key is: 1024D/B0697E48 2007/05/18 Amit Gud <gud@ksu.edu>

Fixing Slab Corruptions

2007-05-18T12:42:00.001-07:00

A while ago, I was dealing with this unwelcomed bug. It was corrupting the slab with occasional oops.

The syslog looked like this:

Slab corruption: 094f77bc start=094f77c0, len=444
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<0811de0f>](ext2_destroy_inode+0x41/0x46)
0f0: 6c 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
Prev obj=094f75f4 start=094f75f8, len=444
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<00000000>](nosmp+0xf7fb7000/0x14)
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
Next obj=094f7984 start=094f7988, len=444
Redzone: 0x170fc2a5/0x170fc2a5.
Last user: [<0811dd90>](ext2_alloc_inode+0x14/0x52)
000: 36 8c 01 00 00 00 00 00 00 00 00 00 00 00 00 00
010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

First thing to do while detecting slab corruptions is to enable debug compile flags CONFIG_DEBUG_SLAB, and CONFIG_DEBUG_SLAB_LEAK. Also CONFIG_DEBUG_VM doesn't harm.

Each allocatable memory unit is called an object in the slab terminology. The first line of the syslog excerpt shows where the object starts which is corrupted according to the slab allocator. Slab corruption is detected while allocating an object. Typically, during unallocation the object is "poisoned" (a specific byte value is written at the entire memory of the object) and it is checked during allocation whether the poison values are intact. Thus, if some values are different, it indicates that the memory location was written after unallocation. There are 3 possible scenarios when this can happen:

over-running the allocated memory - writing to address ahead of the end of the allocated memory

under-running the allocated memory - writing to address before the start of the allocated memory

using memory after freeing it

Wrong pointer arithmetic could lead to cases (a) and (b) above. In such cases, the "Next" and "Prev" objects specified in the syslog provide an indication as to where could be the leakage. The "Last user" in the syslog indicates the last function which freed the object. [<00000000>] or nosmp indicates that the object is not used yet.

Since I didn't had much pointer arithmetic in my code, it was likely that I was using the freed memory. The memory in question for me was for an inode. It was freed when all the referenced to it are dropped. Reference for an inode is dropped by using iput.

I audited all the iputs in the code but couldn't find any problems. iputs in my code are the ones that make the code complex. Typical file systems have just one inode per file to deal with, so usually no iputs are involved, as most stuff is taken care of by VFS. But in the ChunkFS case, lot more (continuation) inodes and hence lot more igets and iputs.

Next was to sprinkle printks around to know whats going on. That didn't help either, only it took me more than a day to figure out of piles of logs what is exactly happening and if anything absurd is going on, or if there is any particular corruption pattern. It is stressful as well as fun to build a mental map of the execution paths and the likely values of the variables just by seeing the log. Good, it was (almost) all single-threaded.

I figured that slab are mostly corrupted during creation of continuation inode for directories and in an desperate attempt to fix it fast, I resorted to a debugger. Theres a reason, btw, why theres no debugger in the Linux kernel. Debugger makes developers lazy. They inspect code no more to look for problems but quickly turn to debugging them. While debugging, I looked at the code and I saw where the problem was. I somehow didn't audited the code close enough to catch it. This patch fixed it:

@@ -264,10 +266,10 @@ static int chunkfs_mkdir(struct inode *

        d_instantiate(dentry, inode);
 out:
-       if (parent)
-               iput(parent);
        if (dentry->d_parent->d_inode != dir)
                mutex_unlock(&dir->i_mutex);
+       if (parent)
+               iput(parent);
        return err;

In the code, variable parent is equal to variable dir if a continuation inode is created while creating a directory.

The Graduation Walk

2007-05-11T20:12:00.000-07:00

The defense went pretty well. Was on 2nd May. The thesis looks decent, although I felt I should've had another month or so to be satisfied with whats in there. But, nothing stops me from continuing the project further and keeping thesis updated.

The week after defense was pretty much doing changes suggested to the draft and giving it finishing touches. And yes, dinner with the family of my major professor Dr. Daniel Andresen, once at his house and once in a mexican restaurant.

And finally, I take a graduation walk today with a Masters of Science degree in Computer Science.

Acknowledgment

2007-05-11T20:06:00.000-07:00

"If I have seen further it is by standing on the shoulders of giants."

-- Isaac Newton, Letter to Robert Hooke, February 5, 1675

It would be an understatement if I say I would like to extend my profound thanks to my major Professor Dr. Daniel Andresen for all the support and guidance throughout my Masters and thesis. I have learned a lot from him, both on the research and non-technical side, and all that will help me in my future. And I would also like to thank him for being generous for allowing me access to Nichols 119 lab, where I spent most of my Masters life.

I would like to thank my committee members, Dr. Gurdip Singh and Dr. Mitchell Neilsen for being patient while I worked on the thesis topic and also for supporting me during my Masters. Special thanks for the excellent graduate-level courses they offered.

I would like to extend sincere thanks to Valerie Henson for having faith in me while I explored the topic in the thesis further. Without her constant support and positive energy this work wouldn't have been possible.

I owe a lot to Rik van Riel for having enormous confidence in me and this idea. I was glad to have interacted with him on numerous occasions discussing ideas and learning. He was the guy I would run to whenever I had problems. I thank him for all his support. I also thank him for introducing me to number of Linux file system folks. I would also like to thank Arjan van de Ven, Zach Brown, Peter Staubach, Garth Gibson, and Stephen Tweedie for sharing their thoughts on this topic. All of the input was crucial.

Also thanks to Dave Jones and his blog that allowed me to have a wonderful summer in Boston interning with Red Hat, Inc., from where this work fruitioned.

On personal side, I would like to thank my parents, to whom this work is dedicated, for their unparalleled care and love. I hope, with all my work throughout my Masters, I'm able to make up for at least something for the time that I could not spend with you. Also I would like to thank rest of my family for all the laughter and being with me during all my times throughout my education so far.

I have thanked just a small fraction of people who have been instrumental for shaping my career so far and I ask forgiveness from those who have been omitted unintentionally.

Thank you all!

[RFC] ChunkFS: fs fission for faster fsck

2007-04-23T16:25:00.000-07:00

I had pre-decided to send out the code on this day. Very early morning I posted it out on lkml and linux-fsdevel. Though its far from anything even usable, its out just to get some eyeballs and help me decide hows it going. Meanwhile I'm trying to get some test results and write remainder of my thesis.

Nothing special today, except for the mundane work :) Happy birthday to me.

PS: Oh, yes, I made up the subject of the patch a moment before sending it, previously I had set it to "divide your fs for faster fsck" or something.

Knowing People

2007-03-27T14:59:00.000-07:00

I incidently came across a random profile on Orkut and started thinking how sweet people are who take pleasure in doing simple things, who like being simple...and at the same time care for not-so-fortunate people around them.

Also, a very good story on the lives of diamond diggers of Sierra Leone. Thanks Viv!

All this and many other things reminds me that how greatful and thankful should we be of our lives and at some point we should definitely put part of our time and energy to the use of such not-so-fortunate people (windows users included ;)).

Those continuation inodes

2007-03-26T13:55:00.000-07:00

So far, though I've been quiet lazy, coding kernel chunkfs didn't feel like a very big task...things pretty much falling in right places. The continuation inodes are working fine now...both the cross-chunk links and the file spanning multiple chunks. Ripping off the existing ext2 driver was probably a good idea to shorten the development time drastically, and still get all the ideas implemented. Need to soon wrap-up writing the dissertation!

As flat as Kansas

2007-03-25T20:40:00.000-07:00

Its the end of spring break and I can wait no more to write a post about our Colorado trip that we had last weekend. I was waiting for photos so that I can put some here. But nevermind, posts doesn't cost any :)

Since I don't have any courses this semester, I don't have much a feel about spring break this year, except for the fact that libraries close early and theres unusually small number of people moving around.

Being in KS and not visiting Colorado is foolish! So, to avoid ending up in that category and to get out of this flat land, I and my prodigal roomies decided to drive to Colorado Springs, which turned out to be a heavenly experience. It was as beautiful and scenic as it could be! I think this is really a very good time to visit places like this..when the mountains are still covered with snow so that you can do all the snow adventures, like skiing and all..but at the same time don't have to shiver too badly due to bad weather. The weather was just right..no problems whatsoever.

The world's highest suspension bridge, the Royal Gorge, which connects two gigantic mountains with a small stream of river and a railway line right in the heart of the valley in between. Seeing down from the bridge is scary! Especially seeing down from the crevices of the wooden planks of the floor of the bridge! But whats scariest is the "world's most scariest ride" (one of my friends told me..no official confirmation on this - but experiencing it makes you realize it is ;)). Its kind of the swing, except that its right at the edge of a mountain and you swing half way through the 1400 feet deep valley. I partnered with suppu for this joy ride. Most heart throbbing part of the ride is when you are lifted to a height on the ground side attached to a rope on your waist and at the count of 3 asked to pull a trigger that is on your right hand side. The moment you pull it, you head straight towards the valley with about 60 kmph! Its like pulling the suicide trigger! Fun!

Most of the stuff that we had cooked (batata wada, sabji, and some gujarati yummy thing I don't remember) for ourselves went bad due to our stupidity of letting it exposed to sun, while we did these adventures :(

Amongst the 4 days in all, 2nd day we spent at the Garden of Gods. And the rest at Estes Park and Ice-tubing at the Summer Gardens respectively. Each passing day we felt today was more fun and wonderful than yesterday! The entire trip was fun-filled and filled with stomach-aching jokes and raptures! Though everyone had in their minds, we all buddies will be floating distant places like wooden blocks on the ocean in couple months time.

I must admit that this trip brought me real joy! I'm glad I was there! :)

Debugging in UML

2007-03-16T11:26:00.000-07:00

User-Mode-Linux is a blessing for file system developers. Have been using it quiet some time now. But lately, for some reason breakpoints won't work in gdb. The execution just didn't stop at the breakpoints. I figured an alternate way to make the execution stop. Let me document it before I forget this again ;) It works like this:

$ gdb ./vmlinux
(gdb) handle SIGUSR1 pass nostop noprint
(gdb) handle SIGTRAP nostop noprint
(gdb) run

Above commands tells gdb to pass the SIGUSR1 signal to the program but don't pass SIGTRAP. SIGUSR1 is used by UML internally. Recall that, SIGTRAP signal is used by the debugger to stop at various execution points in the program that is being debugged. So we don't want this signal to be passed to the program. After this, simply run the program, assuming that you want to have a breakpoint later in the program.

When you want to have a breakpoint to be placed, signal INT to the debugged program, vmlinux is this case. This can be done by firing up another terminal and giving following command:

(gdb) kill -INT <PID>

where <PID> is pid of first vmlinux process running (there are usually multiple vmlinux process spawned by UML). With this gdb will give you a prompt where you can set up a break point, e.g.:

(gdb) b ext2_fill_super
(gdb) continue

And continue executing. Execution will stop at the set breakpoint.

If you want to have breakpoints right while the kernel boots, pass the INT signal as soon as you run the program in gdb.

Handache

2007-03-08T20:02:00.000-08:00

After almost 4-5 freezing months, finally today we were able to get our cricketing gears out. We usually play outside our department on the roads. Only 4-5 of us used to play, but now number has increased. But while bowling today, I think I got a muscle pull on backside of my right forehand and so whole of my right forehand and even the palm is in pain :| This pain reminds me of pain I used to have when used to play dhol and dholki whole lot during Ganesh festivals, when my hands used to ache for whole nights!

At half a dozen decades of life

2007-03-08T08:36:00.000-08:00

At every stage of life, theres a struggle. Years keep flying away and an average man keeps slogging for most of his life - tackling problems which just seem to manifest themselves in different shapes and forms after every while. After all this, whats important is to have uncountable number of people having goodwill and a word of praise for him...for they have seen it all - all his struggle, and all his success.

My sis just sent me some snaps of celebration of my Dad's 60th birthday. They missed me, but they didn't wanted to miss out on the occassion and so had a house full of people - my whole family, its a big one! He turned 60 on 25th Feb.

Tales of his struggle which I've heard from my mom and his friends have inspired me for most part of my life. At my 60, like him I want to look back at life and say with a smile of wisdom and satisfaction and with a benign glare...wow, what a thrilling ride! Lets go further!

Nyquil

2007-02-23T22:04:00.000-08:00

Why can't I sleep early, even with a big-enough dose of Nyquil? I'm not an insomniac! But I think its those hot waves that dash against my eye-lids thats keeping me from closing them. (no, "<ESC> :w" doesn't work here...its not vi, its blogger!, are you sick?!?) BTW, coding actually works even when you're dizzy..and feeling sleepy, though not recommended! Could make you yearn for your sleep.

If you feel like having some temperature, and / or have body-pain lasting for more than a couple days and even if you've not taken health insurance and have tons of thesis research / coding to do...with actual write-up nowhere in sight.....take a FLU shot!

Nishabds' Rozana musical notes

2007-02-21T20:22:00.000-08:00

This is my first attempt to publicly post any song notes. I tried this on my CTK-411 casio. This song seemed pretty simple one...seems BigB can actually sing in almost 1 & 1/2 octaves! The whole song is around chords C# and F# as far as I see...but even C# sounds OK even if played throughout. F# is particularly used when note B is used. I've borrowed the lyrics with some modifications.

Music is beautiful, in the sense its again open-source...you just need to have the right decompiler - and its yours to keep and use. I'm working on mine :)

Enjoy the song! Corrections, suggestions welcome :)

Printer-friendly version here.

-------

Song: Rozana OST [Nishabd]
Film: Nishabd
Singer: Amitabh Bachhan

Major chord: C# (Sa in the classic notes)

NOTE: C#+ means C# in the next octave and similarly
A#- means A# in the previous octave

Rozana Jiye Rozana Mare
Teri Yaadon mein hum
Rozana

Ungali teri thame hue har lamha chalta hoon mein
C# C# C# C# C# C# C# C# C# D# F D# C# C# F

Tujhko liye ghar lautu aur ghar se nikalta hoon mein
C# C# C# C# C# C# C# C# C# D# F D# D# C# C# F

Ek pal ko bhi jata nahi tere bin kahin
F F# F G# F F# F G# F# F# G# A# G#

yun raat din bas tujh pe hi bas tujh mein hi
F F# F G# F F# F G# F# F# G# A# G#

Lipta rehta hoon mein
F# A# G# F# F D#

Rozaana 3
F F C#

ummmm rozaana
D# F F C#

Rozana Jiye Rozana Mare
G#A#G# FC#+ G#A#G# F#C#+

Teri Yaadon mein hum
A# A# C#+ A# G# G#

Rozana Jale Rozana Ghoole
G#A#G# FC#+ G#A#G# F#C#+

Teri Yaadon mein hum
A# A# C#+ A# G# G#

< same as above... from ungli to ummmm >
Har din teri ankhon se Duniya ko takta hoon mein
Tu jaise rakhti thi ghar vaise hi rakhta hoon mein
Teri trah sang sang chale yaadein teri
Yun har ghadi baaaton mein bas
Baaton mein tere
gumghzaa Rehta hoon mein
Rozaaana 3
ummmmm rozaaana

Kuch gaao to yaad aaate hooo
C# C# C# D# F D# C# A#- A#-

Gungunao to yaad aate hoo
C#C#C#D# F D# C# F F

Kuch phehnu to yaad aate hoo
C# C# C# D# F D# C# A#- A#-

Kahin jaau to Yaad aate hoon
C# C# C#D# F D# C# F F

Kuch khone pe yaad aate hoo
F# F# F# F F# F A#F# F#

Kuch paau to yaaaaad aate hoo
F# G# A# BC#+sss B C#+ C#+

Rozana chale yaadon mein teri
B C#+ B G# C#+ B C#+ B G# C#+

Zindagi ka safar
A# B C#+ BA# G# G#

Tujhse hai roshan tujse hai zinda
B C#+ B G# C#+ B C#+ B G# C#+

Yeh dil ka sheher
A# B C#+ BA# G# G#

Yeh dil ka sheher
F#A# F# F D# D#

rozana
F F C#

--
AG
May the source be with you.

Freezing Valentines (belated)

2007-02-19T13:44:00.000-08:00

13th was a long day. Starting from sunny beaches of LA, Santa Monica, I flew towards the snow deserts of Pittsburgh via Cleveland. Landing at Cleveland was a memorable one. It was cloudy, snowing and windy with just a quarter mile visilibility. The plane was descending, but we couldn't guess where. We could not see anything until almost we actually touched the ground. The passengers actually cheered and clapped for the pilot for a safe landing!

The connecting flight to Pittsburgh, however, was cancelled, and I had to stay overnight in Cleveland. Found a cheap place and stayed over. Never saw so much of snow before..the ride to the hotel was almost driving through a river covered with snow.

I had an early morning flight, as it was scheduled, but I was wandering around the airport until early afternoon..since the whole airport was on a ground stop. Ultimately Gary, an elderly person I met while going to the hotel last night, and I decided to pool-in a car and drive down to Pittsburgh. We found another couple who were stranded like us..and they wanted to join us as well.
So it was fun drive..with no stoppages at all..except during getting our car out of the parking lot of the rental office, where it got stuck in knee-deep snow. We had to get out in chilling wind and shovel the snow and push the car to get it started. The rest of the ride was smooth, thanks for the turnpike. Equally long 14th ended with a sandwich watching movies on HBO in Pittsburgh.

BTW, bumped into couple real-super treat for the ears -

'Saang Sakhya Re' by none other than Sandeep Khare and group -
http://www.dhingana.com/albums.php?value=MTE4NA%3D%3D&category=&lookfor=MzU5NjE%3D

This group's previous albums 'Ayushyavar Bolu Kahi' and 'Divas Ase Ki' is also a delight (some songs, if not all) and for the most part couple songs in this new album are upto the expectations. WARNING: Could put to sleep if listened while making broken code work ;)

Nishabd's Rozana by BigB -
http://www.raaga.com/channels/hindi/movie/H001127.html

Thanks Sandhu for pointing me to this, had listened to part of it in a trailer while in India, but the complete song is a treat. Its not just the voice of BigB that makes this song special (I wouldn't argue if someone else would've sang it better), but both the lyrics and the pace of the song are good.

The raaga.com copy is apparently broken. But both the above albums can be downloaded gratis at www.cooltoad.com :)

The Lag

2007-02-02T15:16:00.000-08:00

Going back home is truly rejuvenating. But again departing back from home is not-so-good feeling...and as one of my friends suggested, I just didn't think (much) about it as I was departing...exactly a week ago. This vacation have left with me tons of memories which will serve me good for a lot of time to come.

What really impressed me in this vacation about India in general were growing (and high paying) jobs and bollywood music. But degrading work quality in the IT companies and growing disinterest among new generation to have higher education is something I felt sad about.

Even after a week, as I sit here in the Hale library sipping french vanilla, I feel my home is just somewhere round the corner of the road thats outside this huge window I'm sitting besides. I now feel home is more closer to me.

Happily, coding is my main task this semester apart from TA task of a graduate course which, interestingly, I haven't taken...so some classes as well.

BTW, marathi song collection at dhingana.com is good to get over the jetlag (neat interface and nice collection is something I really liked about this site, plus the audio quality is pretty descent...and all this without any stupid ads - thanks sis for the link :)), which I'm still troubled with. I was recently told by a professor that on an average it takes an hour a day to get over the jetlag. So it seems its 5 more days for me.

Welcome to Life!

2007-01-17T00:23:00.000-08:00

Its been over a month I came back to my home after a year and a half long wait. I would disgrace my feelings of those precious moments I've been through if I try to narrate those here. Only thing I can say is life comes with all the shades...you have to wait and be patient to see them all and enjoy the ride.

More later. The home landline is dead as usual, and I'm using some net cafe connection, and its time to go.

Me falling..

2006-12-12T01:22:00.000-08:00

I'm listening to Roobaroo and Kase Sartil songs, the ones which I always listened for quite a lot of time now...lots of sentiments attached with these songs...the smell of AC air of summer in US, snowfall of December, Houston trip, movie night-outs, ... lot of things...its coming to me like a flashback. I'm just a day away from the day I awaited since the past couple milleniums... I know where I should be. I've missed my place like hell, and I now can't wait to see my dream coming true...I want to go home! I hope I hold up myself for these last remnant hours....like one of my friend puts it - its inexplicable and unbelievable I spent such a long time away from my home - and its not been any easy!

The Climax

2006-12-07T17:45:00.000-08:00

Everytime I fly out of KCI, I think, "OK, now its the last time before I fly out for the des." But its just not happening, I think I'm being teased! But now just 6 days to go, I'm now sure, the next time I'II fly it would be for a land far far in the east...where I've been (senti-)mentally all the time. The climax is not far, but the times decided to run slow.

Rise and Fall

2006-11-16T15:51:00.000-08:00

27 days to go :)

India Nite

2006-11-14T19:12:00.000-08:00

I was as awful as I could..it wasn't the stage fear, it was the lack of practice. Can't complain actually, just had couple of days. And was difficult for a newbie like me who never performed in front of more than 4 people and had started self-learning just couple months ago. Played casio on around 4-5 songs in the annual program gathering of around 300 people that Indian Students Association arranged here at k-state on Sunday. I think I should often go to garage sales, from where I picked up this casio :)

SEA to KCI

2006-11-14T18:38:00.000-08:00

OSDI was fun..was a nice short break. Seattle is a nice little place. The return journey took my entire day, this happens when you plan a trip a month before :| After many people insisting, I couldn't afford missing visit to the Space Needle (wikipedia entry is better than the official site ;)) and the EMP (thats Paul Allen's another toy house, Experience the Music Project). Although I had planned to visit both, they are just side-by-side, I could only visit Space Needle and with around 45 minutes left to spare, the ticket vendor at the EMP generously advised me not to rush through it, as it won't be worth it. The architecture of the EMP is as crazy as it could be! Letting the EMP visit go, I wandered around more, collecting sovenirs and stuff.

I thought I was on track and on time. I didn't anticipated the time it'II take me by bus to get to the airport. I had to hop around to get to the airport, and boy, I now just have 30 minutes to take-off, and I haven't even checked-in! The guy making the boarding pass gave me a pale look and said, "Let me see if you're not too late." He checked me in saying, "This is the closest you could ever get! Run, and get checks done." I had to. The line for the check was tooo big (SEA is a small airport, smaller than KCI!) finally I got the checks done and it was 10 minutes to the take-off and I was still outside searching for the right gate. On finding it, the boarding pass checking lady saw me and stopped another guy entering the plane gate saying, "Another customer showed up." So close! Finally I got in the plane just couple minutes to spare, with the officer's words echoing in my ears, "this is the closest you could EVER get!"

Rest of the journey was fun, and now continental is on my "preferred" list of airlines. They screened Little Man!

(originally written a week ago)

OSDI 2006 - Day 3 and HotDep 2006

2006-11-09T21:55:00.000-08:00

Day 3 of OSDI was mostly "all distributed." Ended at around noon, and then continued as HotDep. It had some interesting papers and did put forth many interesting ideas. Chunkfs paper was presented by Val, and was well received. The intention of HotDep was to get the ideas out for discussion and was achieved pretty satisfactorily.

During long lunch, lasting ore than 90 minutes, I managed to wander around the Seattle downtown. The downtown full of steep roads, is nothing but ridiculously expensive. But even though for one shop I had to go beyond window shopping to realize that its sometimes good to skip lunch. It was a grand piano shop.
One (master) piece that I was looking at was made early in the century and was brought from New York. The shop attendant, with the coat and bow attire just like the pianist ready to play in an concert, explained the history of that piano in brief. He, himself, was a great pianist. His fingures just danced on the keys creating pleasant sound echoing throughout the grand shop. I didn't tried to play it myself, respecting the age-old piano and the attendant's piano skills (and his ears too ;)). It was for some $ 84K odd.

OSDI was fun! Operating systems researh is hot as always, and Linux rocks! Its baby of every OS researcher now, its everyone's tools, everyone's testbed. Plenty to takeaway from OSDI and HotDep! Thanks to USENIX.

OSDI 2006 - Day 1 & Day 2

2006-11-07T23:30:00.000-08:00

Seattle is not so different than Boston, both are a typical American metros, both have some waterbody and both are big. Execpt that it rains a lot in Seattle and there are noticeably many homeless in Seattle. Public transport has good connectivity, but its necessary to make sure you have change before boarding a bus. Starbucks is at every nook and corner of the city, unsurpringly enough, since it was founded here.

Here for a conference and Workshop, OSDI and HotDep, by the courtesy of USENIX Travel Grant. The conference is amazing so far. The attendee list is almost who's who of the OS research including Andrew Tannenbaum and many professors and industry people whose homepage I've visited at some point. Its good to have all such people under one roof brainstorming. Undoutably, its motivating to talk and meet with such people and get inputs on the current hot topics in OS and about the filesystems topics that I'm exploring. It feels good when people already knows about your thesis research even before you tell them about it :) But at the same time it makes you feel all the more responsible for putting extra efforts in your work.

Being a premier OS conference, talks at OSDI are always interesting, and this year was no exception. Most noticeable was "Rethink the Sync," which talked about achieving performance closer to asynchronous I/O but with synchronous guarantees. Among others was one describing virtual memory model for garbage collected applications called CRAMM and OS profiling and state monitoring tool called "Flight Data Recorder."

On day 2, most influential talk was about how Google manages its data storage by a storage system called Bigtable. It gave a birds eye view of the work, but was good enough to let the audience know what it is. There were huge questions everyone had about this...and unsurprisingly the first one to question was a guy from Yahoo :)

With a quick lunch I managed to take some time off to wander around the Seattle downtown. Of course after taking care of the homework that I had to turn in today ;) Conference hotel being at the heart of downtown, every area of the downtown was reachable and I could lay my hands on some stuff for the home coming 2006. Its called the "Public Market Center" and is no different than the camp's fashion street of Pune minus the chaos. Most shops also were speciality stores, like having antiques or some having arabic goods, all wooden decoratives or some even having just black magic stuff!

Evening was spent at the Museum of Flight, which is a Paul Allen's own toy room, so the evening was sponsored by Microsoft and turned out that the USENIX luncheon was better than the dinner :| Along being a museum of flight, it also hosts Leonardo da Vinci's museum. It had nice little models that leonardo had thought about during his 67 years of life, making him greatest of inventor ever! His 13,000 pages of written work is incomparable to the all OSDI-like conference proceedings combined ;)

Sleep calling..

Surya Nagri (a.k.a. Sunnyvale, CA)

2006-10-29T17:32:00.000-08:00

The bay area climate is unbeatable..is just too good. Was there for a quick 3 day visit. Actually the city isn't different than any other Indian metro, except that it had many non-Indians too ;) Every taxi I took was driven by an Indian. Surprisingly enough, the driving license test in that area is also available in Punjabi! Being like any other Indian metro, plently of Indian restaurants..the one at which we stopped was relatively vacous, but we had to appreciate the hospitality of the restaurant owner...he got us chicken biryani without us even ordering it (lol!!)...and it tasted good too, so we appreciated it even more.

Last week made me took an exam which was nothing far from awful. Also I got to hear Vinton Cerf, one of the fathers of the Internet, who was here as a guest speaker at the Provost Lecture Series. He empahasized topics such as role of QoS and internet enabled devices in the future of our connected chaos. He also talked about the Inter-Planetary Networks that he is working on currently with NASA. But to my surprise, he didn't touch upon the role of Social Networks in the coming years. This was followed by my own talk in one of the undergraduate Operating Systems class. Was on file systems and things that I am working on recently.

Chunkfs, a recovery-driven file system design approach

2006-10-01T20:58:00.000-07:00

Its blossoming and slowly starting to take shape as a form of numerous hacks in the actual ext2 driver code, but still a looong way to go.

Chunkfs is an application of file system design approach for easy and fast recovery of file system after system crash and is going to be my thesis topic. A preliminary paper, entitled "Chunkfs: Using Divide-and-Conquer to Improve File System Reliability and Repair", accepted at Usenix HotDep 2006 can be found here (once its ready to go public).

Git repository for the prototype implementation in FUSE (File System in Userspace) is at: git://cislinux.cis.ksu.edu/fuse-chunkfs. It requires libext2 and libfuse.

The tools for the same (fsck and mkfs - both unstable) can be found at: git://cislinux.cis.ksu.edu/chunkfs-tools

Gandhigiri..and chords

2006-10-01T20:41:00.000-07:00

After a strong recommendations from near and dear ones both far and near, I had to watch this movie..Lage Raho Munna Bhai. Especially when its going for Oscar Nomination.

Its crisp and has a terrific plot. Not that the ideology is new, but its application is contemporary. A good watch :) And its even better after a belly full of Malai Kofta, Aalo Vada, Kadhi and Veg-Pulav :D prepared for the potluck in the apartment after which the movie followed.

My goal is to learn piano chords and its amusing me ever since I bought this casio from a garage sale...much time spend on it as well over the weekend.

Fall Break

2006-09-29T18:48:00.000-07:00

It starts from today, but is just one day off on Monday..so not that exciting. But a welcome relief from another hectic week. Exam and lot of TA duties.

I got screwed up on today's exam, I've started enjoying the algorithms class. I wish I had taken it during my Bachelor's, its fun. But I also regret not being able to take AI during my Masters.

Today incidently I bumped into an alumni of my department who graduated in 1990 and was here to show his parents his school. Someday down the line I'II be coming back too..but I'm not able to envision myself after even 10 years.

Social(izing) Networks (Beta)

2006-09-23T14:06:00.000-07:00

I wouldn't thank Orkut in particular. Last 10 days or so I met my old school buddies..one with whom I parted way back in 1992, and meeting couple others a decade later. Socializing Networks (SN) are just a fallout or natural extension to the Internet (extension may not be the right word here).

Theres lot of room for improvement in many of these SNs, mainly in the areas of UI, navigability, and importantly integration with the desktop. I particularly hate going on such websites just to read or write a 'scrap' or such. Its difficult for people, like me, who live in their mailboxes. Apart from this there are innumerable features that can easily go into such networks, increasing user participation. Security is particularly flawed and cases of identity stealing are not uncommon.

There are number of such networks out there. And secondary purpose of each network is different, primary being connecting people together. Not everyone can participate in all of those, and arguably its right too. Most don't want to bare with all of their accounts with for example Livejournal, MySpace, Facebook, hi5, LinkedIn, and Orkut. Atleat I don't.

I see a need and room for a generalized standard for any such SNs. This is needed for allowing the compatibility between two SNs. Apart from enabling single sign-in mechanism, such standard would allow to be able to connect to more number of people from various different networks. This could be more intrusive than just having a wrapper around each such network and gluing everything together.

Its just an early stage, though, for such networks and such networks will play a very big role in Web 2.0.

fuse-ext2fs git repository

2006-09-11T11:12:00.000-07:00

Starting off from jgarzik's fuse-ext2 priliminary code base, this is working implementation of ext2 file system in FUSE. The code is whipped so badly that I'm in no condition to send patches to jgarzik on this. This code is forked from the another file system kiddo prototype that I'm developing, which is based on ext2 and it uses this code. This is part of the reason why this fuse-ext2fs code looks entirely different from jgarzik's tree.

Available here: git://cislinux.cis.ksu.edu/fuse-ext2fs
git tutorial here: http://www.kernel.org/pub/software/scm/git/docs/tutorial.html could be useful.

Requires libfuse and libext2fs.

FUSE is a neat way of prototyping a file system and this fuse-ext2fs would certainly be of help if you want to base your filesystem on ext2 and modify it thereafter.

Soothing, as in after-rains mud smell

2006-09-04T18:36:00.000-07:00

The long weekend took me to the tuttle creek lake for canoeing, and some awesome BBQ :) Those canoes were very small balanced just on a single bar spanning through the length of the canoe. My new casio CTK-411 that I bought out of a garage sale (almost a steal deal) took some of my time. My mom was more happy for me having it, she knew how happy I must be for having it...I wanted to buy it since a very very long time now, but couldn't for some reason.

PS: the title sounds irrelevant after editing the post.

rmmod redhat || rmmod -f redhat

2006-08-20T19:01:00.000-07:00

August 16, 2006 (forgot to publish it ;))

Today it took unusually short time for me to paddle up two miles from my apartment to my office (or atleast I felt so). The last day of summer internship here at Red Hat and just a little more than one year in US made me recollect the entire year that just passed by.

The summer was particularly awesome...and I enjoyed doing things more than anything else in my entire year that just passed. I mostly ended up hacking NFS - fixing bugs and adding trivial features, plus upstream changes to the NFS user-space tools. Also I was involved in a cross-functional intern project chalking out future investment plan for BRIC countries for Red Hat. This work was a good exercise of market research and business planning which I did sometime back, and allowed me to interact with almost all the VPs in the company.

Most importantly it was a wonderful experience to meet very very talented people in this field.

All in all, a great motivating summer. Courtesy Red Hat, Inc. :D

Six Flags, New England

2006-08-15T12:14:00.000-07:00

Heart throbbing, thrilling, palpitating, exciting, nerve wrecking - all together :)

One...and counting

2006-08-02T14:43:00.000-07:00

Exactly one year back (felt like a decade), I landed in US. It was painful, painful to leave your loved ones behind..to come here only to miss them, only to know how much they love you and miss you back home. Its been an year since I saw them. Don't know how many more years I'II have to count :|

Its not that I'm complaining being here, but I'm restlessly missing them (an understatement). Have already got tickets for december...but still its 4 months to go..4 whole months before I see them. When I actually face them I wouldn't beleive its for real...for I've dreamt zillion times about being there (an overstatement). Around 40 days be there...be there, have fun of your life, be a kid and live life - like you used to for the past 20 years of your life...only to come back here again, only to miss them again, only to realize how much you love them and what importance they hold for you.

</homesick>

Back to work.

Setting up a remote git repository

2006-07-30T17:42:00.000-07:00

Just for reference.

1. Download git sources
Grab the latest tarball from http://www.kernel.org/pub/software/scm/git/

2. Extract and do make prefix=. I usually install such things in ~/bin

3. Make sure git binaries are in your PATH

4. 'cd' to the directory you want to start the project in, be it empty or already filled with project source files. Do 'git init-db'. It will respond with "defaulting to local storage area."

5. Run 'git add .', which adds the files in the current directory recursively. If you want to add a subset of files, specify them explicitly.

6. Run 'git-daemon' as appropriate. Use may want to use 'screen' if it doesn't have the --detach option. See http://www.kernel.org/pub/software/scm/git/docs/git-daemon.html

7. Test the setup by executing this or a similar command on a different machine "git clone git://server/git/project"

Alternatively, tools like cogito can also be used which "ease" the use of git. Cogito can be found here: http://www.kernel.org/pub/software/scm/cogito/

That is all :) Happy Hacking!

Record Sleep

2006-07-30T08:57:00.000-07:00

Since I-don't-remember-when (or if ever) I slept so much - 12 hours at a stretch! 6 PM to 6 AM :)

The RMS Encounter

2006-07-28T23:06:00.000-07:00

Being my regular customer, English Zone, asked me to do a story on ~~open source~~ ~~FOSS~~ free software! Ah there you go ;)

As usual I had to hunt for my interviewees. It wasn't that being in Boston made me decide to interview RMS on his favorite topic. I wasn't sure how approachable he is. But a friend of mine and a former employee of FSF told me that I should talk to him. So I emailed him with my intention and questions. There came a real quick reply, auto-generated of course, explaining emailing habits of RMS, and telling me to expect a reply in 48 hours.

RMS replied. Asking me to focus on free software than on anything else and restructuring my story eliminating any references to IP. I was fine with it. I again replied acking to it and restructuring my questions. He came back with the reply after a day's time.

I'm honored to quote him in my story along with some distinguished hackers in the community :)

first photos

2006-07-26T13:25:00.000-07:00

Got my camera shipped, its Fuji FinePix A600, a 6.3 mega pixel camera for less :)

sysctl for the late-comers

2006-07-26T12:26:00.000-07:00

How to set a parameter using sysctl for a module thats going to be loaded at sometime after booting?

sysctl? huh?
- sysctl is a method to change the kernel parameters (from userspace of course ;)) at the runtime. It depends on sysfs and /proc filesystems. More here

Typically the init scripts execute the specific sysctls for the specific modules. But sysctl is wasted and pointless when module is not already loaded at "init-script" time, and when its going to be loaded sysctl will still have to be made for parameter values to reach the module.

So how to do it?

Lets take example of sunrpc module and the parameter being sunrpc.tcp_slot_table_entries.

1. An udev rule is handy:

$ cat /etc/udev/rules.d/23-sunrpc.rules
# udev rule to set sysctl values when
# sunrpc module is loaded
#
SUBSYSTEM=="module" ACTION=="add" DEVPATH=="*/sunrpc" RUN+="/sbin/sysctl -w sunrpc.tcp_slot_table_entries=64"

This rule says - whenever a 'module' called 'sunrpc' is 'add'ed, run the script.

2. Add a line to /etc/modprobe.conf
install sunrpc /sbin/modprobe sunrpc; /sbin/sysctl -w sunrpc.tcp_slot_table_entries=64;

This line says - execute the following command whenever the module sunrpc is being modprobed. And we just insert the module first and then do the sysctl.

3. Or use a method similar to the my patch here, against 2.6.9-42.EL. Its generic enough but there are limitations of this method and I think userspace fix is more appropriate.

Bug closed as NOTABUG :)

time > /dev/fun

2006-07-18T15:17:00.000-07:00

Exactly one month left for my internship here at Red Hat to get over, got really accustomed to the work here, and the routine, and the people, and the culture. Don't feel like going back to school and get burdened with the things that at times make me spend my time, which I'd rather spend on more constructive / better things. But being school work, even that will be duly embraced. But I'II miss this culture for sure. Here people don't work for getting paid, but to passify their grey cells...to chase their passion. And thats what I like about people. Almost half the company is working even on holidays and weekends, and you can make it out just by peeping into the IRC channels, (yes, keeping up to the hackerish norms, IRC is used extensively...its the backbone of the company. Am not sure how many other companies exploit this so constructively.) And when you have such like-minded people around you, work is nothing less than just fun!

After a real long time, today I found myself playing tabla in one of the lawns of the company. One of my Russian intern friend here, who not devout but is just a fan of Indian food, music and all those things that Indian sadhus smoke, bought Tabla yesterday and asked me to give him some lessons, and actually brought Tabla in the office. First I had to teach myself how to play it after such a long time...I've had both tabla and harmonium since I was a kid, prolly 9, I had an inclination towards it, but my mom was a real force behind my learning tabla, but never got to it..just the bascis. Both the instruments are still around, but haven't played them since a real long time. Was a good break though playing tabla in the company lawns :) Imparted my friend with couple of tabla strokes..which even me not perfect at ;)

Prying Bugs II - file handle corruption

2006-07-12T16:32:00.000-07:00

The one on which I'm working on right now is fairly simple to understand and always reproducible. Volumes with minor number greater than 256 are not being mounted. The client process waits for the server response and later dies with EIO.

I started hunting the bug by enabling the available debug info, and it was clear that the client wasn't getting FSINFO reply. A plunge into the code was required to find the reason. For every client, server maintains an authentication cache (export map) and a cache for file handles (expkey map). Since file handles has to be unique within the server, device numbers are used, which are fairly unique. Some client info and device number is used to decide the expkey. However, minor numbers greater than 256 are encoded in a different way, a new encoding logic (which arguably even ethereal doesn't know of, I tried adding it...just added the new file handle version but couldn't do more for lack of time).

After staring at the code for quite a while, I tried lot of debug printing and came to know that fh_verify (file handle verification) didn't succeed. A day later I realized that fh_verify didn't succeed because the expkey cache entry is stale and it never got updated. This was a stagnant phase for some time. Later, after some thoughtful insights from author of original (Sun) NFSv3 and its RFC (1813) (who sits two cubicles away from mine) himself and some more code tracing, I found that the cache should be updated by the kernel when it receives a request for file handle on /proc/fs/nfsd/.getfs or /proc/fs/nfsd/.getfd from mountd.

Then a network trace and a realization that correct file handle is not returned by mountd. This was all due to the different encoding scheme for higher minors. I changed the code which encoded the expkeys of devices with higher minor numbers to the old encoding scheme (as for the devices with lower minor number) and also correspondingly changed nfs-utils. It worked. But I don't know why devices with higher minor numbers are to be encoded differently when we have 32 bits to fit the key into.

This is no way a fix, just a work around, need to lookup where the things are slipping off for the higher minors and why file handle isn't correctly reported.

Right now, time for some weight lifting and biking (which I've started to love) :-)

Prying Bugs I - fcntl / close race

2006-07-12T15:14:00.000-07:00

Recently I've been put into bug fixing apart from the regular chores. Mostly NFS. Last week I was working on a bug in which the locks obtained using fcntl were not gracefully revoked when a process trying to hold the _non-blocking_ lock is terminated abnormally. This was an interesting problem. A very obvious bug, easily reproducible and made me wonder why this bug survived so long? So long that redhat had to hire me to fix this. It is a 2.4 kernel bug. Its even upstream.

When processes died (for any possible reason), locks that are held by the process are revoked while closing the files. Linux kernel maintains locks at two places - in the inode (i_flock) and in a global linked list of locks. Acquiring a lock for any filesystem is easy. Only the conflicts need to be resolved. But for a network filesystem, first call the filesystem lock routine...that puts the stuff on the wire back and forth...and then resolve conflicts, if any. Bug was actually a race between a file close and fcntl, and I bet would exist on any linux network filesystem - for its in VFS itself. This was the scene:

---
P1 requests server for the lock
Server grants the lock
P1 sends release request for the lock
Server grants the release request..

...But before this release response reaches P1 and i_flock is updated, P2 gets
going..

P2 request server for the same lock
Server grants the lock
P2 tries to update the i_flock field, but find conflicts
BUG: error goes undetected
P1 runs and updates i_flock
---

The bug is that, conflict is detected but server is not sent the unlock request, and server thinks it has granted the lock. Remember the locks are non-blocking. Later when you test for the lock, server thinks that the lock is granted and will return the same notification, but in fact the process to which it granted the lock now cease to exist. A fix was to send the unlock in case a conflict is detected after the lock is granted from the server.

Bugs are making me more inquisitive...they increase my hunger and make me desperate to track them down. I'm liking it :)

A Scalable Search Algorithm in Unstructured Peer-to-Peer Networks

2006-07-05T16:19:00.000-07:00

Time for the paper to go public. Can be downloaded as pdf. This paper was published at PDPTA 2006.

Enjoyed thoroughly while doing the project, its on-going. Am not able to recollect where I read, but its true - the time from the inception of the idea to the actual publication is atleast an year. For me it was 13 months.

Another good paper to read - here.

All Rights Reversed.

Open Source - Open Future

2006-06-30T15:33:00.000-07:00

Let figures speak. Linux Server Operating Environment (SOE) market is valued at around US$ 130 million, with almost similar figure for end-user spendings. Its cathing up like a forest fire - estimated to grow at around 31% CAGR from '03 to '08. And still theres whole lot of untapped business out there. Its happening. You understand the unabated revolution thats steadily sweeping everyone off their feet when you hear something like Peru and Venezuela decides to go open source. Its happening, and its going to happen with or without Red Hat, with or without GNU/FSF, or with or without Linus Torvalds.

At this point it is important for software businesses to consider their business model and have a thought of how it would be in the open future, future when most software pieces would be open source. It is important to understand that except for few specialized verticals, all applications are likely to be derived directly or indirectly from a community developed open source code. This is a drastic change from the conventional business model, where you sell the stuff that you make or that you knew better. Now its different, now you have to sell stuff which is not yours, you just know it, essaintially better.

Trying to sell things which is not owned by us sounds kind of absurd, but thats the new business model all about. Moreover, it gets trickier when we need to sell a thing and make money out of it, when its already available for free (free as in free food). Companies like Red Hat should be truely appreciated for putting forth an example of how a company should be in the open future. It s this new business model that makes mere 1300 people company threaten the business of many hundred thousand people companies.

Back on wheels

2006-06-24T13:02:00.000-07:00

Me moved to a new apartment here, closer to the company, just 1.7 miles. Other person to move in is yet to shift...so me alone as of now. I borrowed a bike from an intern friend who apparently had many spare. Theres no internet connection in the apartment, and no wireless to piggy back ;) But theres this mexican restaurant just besides the apartment having broadband connection. This blog is courtsey of that connection :)

Ride to and from the office is adventurous to say the least, especially at nights. Its cloudy, so no moonlight, and theres not much custom here to have street lights. And its hair raising when you know that on your ride during the day you say creatures like toad and even snake (dead, of course ;) on the road. Take away - ride in the daylight.

Works alright, no complains...more about it later.

Yet Another Weekend (YAW)

2006-06-02T21:12:00.000-07:00

It was pouring down heavily when I came here. Its been three weeks I'm here for work, for some good work and good experience. Had given a choice even in my sleep, I'd have chosen to be at this place. And I soon realized that I made an intuitive choice, despite of having some tempting options. Now I realize what it feels like for getting paid for doing things you are dying to do.

I hope thats the case with most my other friends who are here, and they must have been all set and doing their best. Abhi got hooked up with Borcade, Vivek carrying on with the RA work, as is Sachin, Vaibhav with NetApps, and something hit Kary (on the head) and he is at M$ :P

Although my PhD plans are obscure, almost nonexistent, my visit to Harvard and MIT last weekend urged me to have a thought on that. Was a good time. I and one of my newly found friend here spend some real good time hiking at the Great Brook's State Park and exploring some real good places in and around the heart of Boston city, along with some Indian food, movies and novels.

Its raining again today. Will rain couple days more...have some work and long pending novels that needs to be completed.

Was just interrupted to read a blog post of one of my friends, who is quitting his job to come here for his MS, and there are many of my friends who'II be here this fall in all great schools. It wasn't long when I was on the other side of the table and doing the things they are doing and planning. But it feels a life has passed within this year...really!

Simply astray!

2006-05-25T15:48:00.000-07:00

Maajhich laal

Having look at this would simply scare away new investors and new organizations planning to get into Indian market. How adamant and inconsiderate Indian ministers could be? This is a good example. I can't see we going astray like this with the courtsey of such people. Is Rang De Basanti really in making? If I'd have been in such reservation category, even then I'd have considered such decision just an act out of self vested interest given the statistics in the interview above. Theres this joke circulating around for a while now:

Manmohan Singh to Bush – We are sending Indians to the moon next year.
Bush – Wow! How Many?
Manmohan Singh - 100
25 - OBC
25 - SC
20 - ST
5 - Handicapped
5 - Sports Persons
5 - Terrorist Affected
5 - Kashmiri Migrants
9 - Politicians
and if possible
1 – Astronnaut

When I laugh at this joke, I feel I'm laughing at myself.

Red Hat Boston

2006-05-21T08:49:00.000-07:00

This is my first relaxed weekend after the exams. Its been all travelling.

I'm hooked up with a guy for sharing an apartment and an another guy for sharing a car to the office. Boston is a big city, unlike my school place Manhattan, KS. Here you are paralized if you don't have a car or cell phone. I have neither :(

RH is a great place to work. The people here are awesome and work culture is heaven. I feel like sitting amidst all the big shot celebrity kernel hackers. Theres plenty to learn from each one of these. I don't think any company is so transparent and open to its employees than RH. It truely breeds the culture of open source community. Its like all the people instead of sitting at their own places and doing work come here, do the same things and get paid. What I really appreciated is that every person out here is so passionate about his work and theres all academic environment with everyone still learning and researching. As of yet I couldn't find sandals, but ya pony tails are many ;)

I'II be working mostly on NFS stuff and if time permits also on GFS. Hope will have a good time and hope I'II be able to cope up with these guys :)

Bring'em on!

2006-05-13T19:08:00.000-07:00

13th May 2006 - 10.30 AM

I completely failed to understand one of my friend's post. I firmly beleive that nature *does* conspire to help you achieve things you earnestly long for, provided you put in your hardwork. I beleive that sincere efforts can surely make things impossible plausible (if not possible).

I have some time to kill here at the KCI airport, while I wait for my flight to Boston. I was just dropped by my school shuttle here. Exams were good, not a big deal at all. Sometimes I feel like double-checking if I'm taking graduate courses or undergraduate ones ;) This semester was a hurried one...more swifter than the one before. Most of time was consumed in exploring some new areas, interviews for internship, projects and in finalizing a paper on one of my projects, which I completed last semester. Its on peer-to-peer networks, titled "A Scalable Search Algorithm for Unstructured Peer-to-Peer Networks", got accepted at PDPTA'06.

As the name suggests, it talks about a technique to scale the search in Gnutella-like P2P networks. As the network size shrinks and grows the search algorithm adapts itself dynamically and controls the level of flooding (the number of nodes to which a query is passed). It directly influences the number of messages passed for a query and time required to reach the target node (node, which could satisfy a query). The results are as anticipated and our (me and my two professors) algorithms perform good on both - the number of messages required for a query and amount of time required to satisfy a query (either successfully or otherwise). I had a lot to learn out of this project. I won't be presenting the paper for the lack of funding for attending the conference :( The paper is available here (will be linked off here, once the paper is ready to go public).

Other things that I was working on in the spring semester is still in its nascent stages. It involves more of Machine Learning than of anything else. Will continue to work on that over the summer. I also managed to do an article ( which I regret for not doing often, given that it doesn't take me long to do :( ) for a magazine (EZ) which is my regular customer.

I'm excited to have an experience of US corporate culture. Given that even Indian companies now offer quiet a liberty and flexibility in work, I'm afraid if it would be any different in the US (if at all). Especially in the corporate area where I'II be working, where sandal and pony tail is apparently known to be a trademark, I shouldn't find it too restrictive.

Will be heading for Raleigh, NC for orientation for new hires at Red Hat and will be starting my work on Wednesday. I'm excited to be surrounded by all the kernel developers. Hopefully will have a lot to learn. I'm ready for the plunge!!

Crunch Time

2006-05-02T17:28:00.000-07:00

It always happens. Whenever I'm close to my exams I feel like doing lot of other things...projects and all (and people think I'm busy studying ;)). Though one of the projects definitely needs my attention, others are also getting some over the past week. Lot of things in the pipeline for the coming summer and the semester to follow. All about playing and learning...or learning while playing. Lots of learning.

Oh, ya. This is my first post of my year. I and Shakespeare share same birthday. Lucky him. Gave costliest party ever..got hell lot of bumps.

More on my projects in the posts to follow. Wish me luck...exams in this and next week!

More distros, more chaos (?)

2006-04-18T01:27:00.000-07:00

Company News | Reuters.com: "Oracle says may launch own Linux version"

Linux is already a me-too technology now, and every Tom, Dick and Harry has a distro of his own. There are plenty out there. Just look at the distrowatch.com, even though the list is not exhaustive, its big enough to be able to keep track of. I bet even distrowatch people must be finding it difficult. And to add, there are numerous livecds scattered all over with all sorts of names.

It could be difficult to find a right distro for you. But pretty much is standardized and the application areas of many are well understood - "Which Distro Do You Recommend?" Also unless you have emphatically different or special needs, theres already a distro recommended for you. If not anything, it at least spreads awareness and gets lots of people involved in the process. So more the better?

Its nice to have choice, but its really not good to be overwhelmed with many. Starting a distro for fun its ok, you want to do it just for the sake of learning, even then its acceptable. But when it comes to companies starting out their own..it may not neccessarily help open source as a whole. Also whats getting heavily smacked in such situations is an unified effort to get the GNU/Linux on layman's desktop (the ultimate target!). Oracle buying out Novel would be welcomed more that it starting out on its own, with again a new bundle of things, new way of configuration, new package manager, and so forth. Its working against us. We are scaring away people with this; for the learning curve could be really steep even when it comes to installing a software as simple as IM or watching DVDs.

Again, there has to be some choice and no one distro should monopolize. For the sake of competition and wider options for the user, would be better to see a limited set of distros (and we already have many) backed-up by strong foundations like Red Hat, Ubuntu and like, and not every foundation setting out on its own.

Port 25

2006-04-06T20:25:00.000-07:00

Port25: "Port 25 is open. The people, insights, and analysis from the Microsoft Open Source Software Lab. Send us your feedback and ideas. We want to hear from you."

No its not Mircosoft's April Fool's joke. Its real. The blogs on the site are good, but the comments are hilarious! Being slashdotted already, the blogs are turning out to be a flame war field! Though Microsoft opened up its port 25 (the SMTP port, Did someone say the name is cute?), people already using the site as "why MS sucks" forum. Seems like Microsoft has given out a place for people to rant. I hope filters will be ON soon for the spams, bots and flooders at least (but am skeptical how useful it would be) and such creatures go away from the site in a while so that the site becomes more sensible.

New Trends In Online Traffic

2006-04-05T09:22:00.000-07:00

New Trends In Online Traffic: "While growth is slowing at most top Internet sites, it is skyrocketing at sites focused on social networking, blogging and local information."

Exciting and much anticipated. In fact, I see this growing to an extent where people's only application of use will be a browser. And all the other apps of daily use would be available online and free. No more paying even for a single piece of software, and there'II be just two things that we'II have to pay for - hardware and bandwidth. I see this happening already with the Web 2.0 (good read: The State of Web 2.0). Things like Ajax are sprouting up fast (just like any other tech buzz) but this time its here to stay, or at least here to leave a significant impact and a ground work for the next bigger things to come. Ajax Office is one such example.

So how would companies make money? For a layman with basic needs, paying for hardware and bandwidth will be enough. But there are things that would require fees / subscriptions. Things like professional support services, online media and sometimes the content itself (specialized and filtered, not the Wikipedia types). But there are things that needs a major revamp, especially the UI and navigability.

So I see it boiling down to the Linus Torvald's principle of life, as he puts in his autobiography - Just for fun. According to him there are three things that have meaning for life, which are motivating factors for everything in one's life and determines the progress path for anything and everything in life. These are survival, social and entertainment, and the implication is that the meaning of the life is to reach at the third stage. Every technology follows same path as well. Initially Internet was limited to defense localities - was a support feature then, meant for survival, now it has become a social thing..and slowly we are reaching the final stage of the game. It has started to become a mere means of our entertainment.

It feels good to be at this stage of the transition and would be awesome if to be able to contribute in any ways.

Friends forever

2006-04-04T08:59:00.000-07:00

From one of my friends:

"hi amit, how r u? what about ur studies? rajesh's brothers' wedding reception was on 2nd april, mast majja aali, tuzi khup aathavan aali pan kay karnar, mhanun sarvani tuzya navacha ek-ek ghas kadhun thevala:)). ok what else, take care, keep smiling bye"

Miss you all too :)

The Source is with me!

2006-04-02T22:10:00.000-07:00

I don't falter (for some obvious reasons) to accept that open source philosophy has always motivated me and have provided me with opportunities to learn. It has always been something that pushed me to know things and has put my time in doing some useful things. I thank our senior, Sandeep Sahu, who was the first guy who introduced me to Linux and open source and got me started. It was back in second year of my Bachelors when he conducted after-school lectures for those who are interested, just to spread awareness...and it was inspiring!

It started with installing and getting used to the new operating system. I was having a shell account for internet connection during my high school and I was given a Unix-like prompt with pine, lynx and ircii. I didn't had a clue what system I was using...for me it was just a means of getting on the Internet. (It was a student account with a dial-up connection, and while purchasing one..I didn't had any idea that it will be adding to my phone bill as well ;)) So this was the background I had when I started with Linux, it did helped to some extent but not a great deal.

After tweaking around for a while...experimenting with all the eye-candy stuff (which I still do)...I started user-level programming (gtk, qt, shell, php), and then some kernel-level stuff too. Was fun...there was no one to teach..it was just the forums, online tutorials, man pages and IRC. Once I started that..I felt (as usual) that I started late. But nonetheless at least I got started! When there are lots of things that help you learning new things, you feel like learning. There were/are resources which help in learning things, especially when it comes to open source...they won't spoon-feed you, but will at least provide you with pointers. And many a times that is how it should be.

Am not anti-closed source, but I feel knowledge is there to be shared..that is how all scientific developments have taken place. Without reinventing the wheel, learn what others have done in the past, try to improve it if you can..and if you do, don't forget to pass on what you learned. That simple is the philosophy of open source. It is powerful, motivating and most of all, it works!

I'm glad that I'II be around such environment for some time now. And would be a good summer experience at Red Hat, Inc. *wink*

Time is fleeting fast..already at the end of second semester...will finish off coming fall fast with a pleasing feeling of going back home in December, and then MS almost over. So fast, so swift.... But yet theres lots to learn and lots to earn (apart from money). May the Source (in every sense) be with me like this forever.

And may the Source be with everyone too!

Ok, gotta go...me need to find a place to hang my hat ;)

Todays Headlines

2006-04-01T11:24:00.000-08:00

Seems like world changed today!

China buys Google

UK Government to shut down GSM networks

Google launches Google Roamance

Microsoft buys OpenOffice.org

MY PICK!
New system call - int is_computer_on(void)

Yesterday we had a python in our apartment, a friend of mine got a snake bite and I was fired from my school ;)

Happy April Fool's Day :)