Sunday, February 26, 2006

Disk scheduling cont'd

So I generated some artificial disk traces with the requests being sorted in CSCAN order. Using these disk traces, I tried out the CSCAN and the Dynamic Programming (DP) algorithms to measure the average wait time. The DP algorithm did show a significant improvement over CSCAN, but I had not included the table construction phase during the calculation. But my guess is since the memory for the table was pre allocated, this should not affect the calculations that negatively.

Disk scheduling using dynamic programming




Very much inspired by a research paper by one of my professors (Dr. Geist) at Clemson. The paper can be found here

Saturday, February 25, 2006

Iqbal

Saw the movie "Iqbal" yesterday. The movie is based on the famous Indian game of cricket. Although I am not a big fan of the game, I really loved this movie. The reason being it signifies "The triumph of the human spirit" without any usual stupidities of Bollywood. Very inspiring and motivational.

Friday, February 24, 2006

Early Morning


I woke up at 6.30 am this morning. I do not recollect waking up so early since a long time. It was wonderful to see the beautiful sky and hence I decided to click this picture from my balcony.

Sunday, February 19, 2006

Getting DiskSim 3.0 working on Fedore Core 3

Downloaded DiskSim 3.0 , Disk Simulator used to study the performance aspects of storage systems. However I had some problems getting the simulator working on Linux Fedora Core 3. After a couple of hours of playing around with it, I finally got it working. Also I have posted a patch on my website, so that someone else can get the simulator working without going the pain that I went through. However note you need gcc295 (version 2.95) to make the simulator. Have fun!!!

Thursday, February 16, 2006

Lock up

I decided to head to the bathroom before crashing into my bed tonite. However when I tried opening the door I realized that the bathroom had been locked from inside!!! Damn, it was a frustating thought. I think Om must have mistakenly kept the knob of the bathroom door in the lock position after using it. Om is a friend of my under graduate friend, Siddharath and has been staying with me since past 3 days. He will be moving out tommorow.

Anyway being Engineers we decided to open the knob without the a key. Om tried using a safety pin by inserting it in the hole of the knob and rotating it. The knob was basically a privacy door knob and was suppose to open without a key. Apart from pins, the other objects that we tried as a part of the stunt were scissors, knives, forks and screwdrivers. I even googled to find an answer to the physically frustating problem. I found a link here but was of hardly any help. Half an hour had past and I was about to explode.

Since none of the techniques work, we decided to educate ourselves by solving a similar but easy problem. In short, we decided to experiment with my bedroom knob so as to understand the mechanics behind it. We purposefully locked the knob and then unscrewed it and using scissors rotated the inside shaft and finally unlocked the door. Hurray!!! We simply needed to apply these steps to the bathroom knob now. So after fixing (screwing) the bedroom knob, we again attacked the bathroom knob problem with our newly acquired knowledge and unlocked it as well.

I was relieved mentally as well as physically :) with the unlocked bathroom. Also I was enthusicatic enuf to write this blog about the misadventure. Anyway I will sleep now. Good Night World.

Mission Kashmir

Was listening to songs from Mission Kashmir, Tanu and me love them a lot....

Saturday, February 11, 2006

Adding new I/O scheduler to the 2.6 Linux kernel

1) Put the I/O scheduler code in drivers/block/ and add the information to the Makefile inorder to compile the code
2) Modify elevator_setup_default() in elevator.c accordingly

Tuesday, February 07, 2006

Solaris Performance Monitoring

Click here

Wednesday, February 01, 2006

Tanu