topic Re: faster file system in Operating System - HP-UX

faster file system

Shivkumar — Sat, 14 Oct 2006 12:54:18 GMT

Hi,

We prepare builds for j2ee applications but it takes 3-4 hours.

Shall we perform this build in /tmp which is very fast as /tmp doesn't use file system ?

Are any idea how to reduce build time ? Our system already has 4 cpu.

Thanks,
Shiv

Re: faster file system

KapilRaj — Sat, 14 Oct 2006 13:01:18 GMT

Needless to say it's a poor question. Can you explain what you are looking for ?. /tmp not uses a file system means what ?

Regds,

Kaps

Re: faster file system

Steven E. Protter — Sat, 14 Oct 2006 13:04:57 GMT

Shalom Shiv,

Suggestions:
vxfs is the best file system for HP-UX. There were noises about using adfs from Tru64 but that never seemed to materialize.

Post your filesystem mount options from /etc/fstab and I and others will make suggestions on how to improve write performance.

Note also that filesystems on raid 5 devices do writes(ie compiles, builds) more slowly than raid 1 or raid 10 due to the number of places writes have to go to on a raid 5 device.

Note further that compiles are CPU and memory intensive and more memory and faster or better CPU's will normally have more of an impact on compiles than anything you can do to the filesystem mount options.

SEP

Re: faster file system

A. Clay Stephenson — Sun, 15 Oct 2006 19:31:14 GMT

Reading between the lines, you must have /tmp mounted with the vxfs nolog option which sacrifices recoverability for speed. First, you shouldn't be using /tmp at all; /tmp is for the use of the OS not for user processes. Secondly, have you determined that i/o is the bottleneck? You might try creating a filesystem and using the nolog mount option and see if it makes a difference. In any event, you must identify the bottleneck(s) and then plan your attack.

Re: faster file system

Bill Hassell — Sun, 15 Oct 2006 20:11:10 GMT

And to amplify Clay's repsonse a bit...you J2EE apps don't build just in /tmp. If you examine all the filesystems, I'm sure you will see that many different filesystems are used at the same time. The fact that some of the output and temp files go in /tmp is only a small portion of the system activity. I'm confused why you think /tmp is very fast because it doesn't use a filesystem. If you can store files in /tmp, then it is a filesystem.

To improve the speed for the builds, you have to:

1. reduce the amount of disk I/O
2. increase the number of processors
3. move the busiest directories to an external disk array with lots of memory, or use a solid state disk.

You can't really assume that the filesystem is slowing things down until you analyze the actual resources used on your system during the build. This will take quite a bit of effort if you don't have Glance installed.

Re: faster file system

Shivkumar — Sun, 15 Oct 2006 23:12:19 GMT

Thanks a lot to Steven, Clay and Bill for their great explanation. I will examine the issue per your suggestions.

warm regards,
Shiv

Re: faster file system

Yogeeraj_1 — Mon, 16 Oct 2006 00:11:47 GMT

hi shiv,

Please allow me to also add that J2ee applications are mostly cpu intensive.

During the build operation, you must observe the resource utilisation (Memory, CPU, Disk) - one good tool would be measureware.

I would also suggest that you find a way to run the build operation in parallel to speed up the process.

Also consider contacting support (if any)

hope this helps!

kind regards
yogeeraj