topic Re: Changing maxfiles_lim in Operating System - HP-UX

Changing maxfiles_lim

OFC_EDM — Wed, 06 Feb 2008 14:19:55 GMT

maxfiles 2048
maxfiles_lim 2096 -> want to change to 8096
ninode 3140
nfile 31289

Reason for change:
Processes are running out of file descriptors

My Question:
The request is to change maxfiles_lim to 8096.
But I'm thinking this will effectively be the same as setting maxfiles_lim to 3140.

Because don't you need an inode for each file open? So if you set maxfiles > than ninode anything above the value of ninode wont have effect?

Cheers

Re: Changing maxfiles_lim

Steven E. Protter — Wed, 06 Feb 2008 14:57:11 GMT

Shalom,

ninode has nothing to do with max files.

Go ahead ame change maxfiles and maxfiles_lim to the new level.

Remove any formula problems that result from this change.

You ninode level is pretty low and should be increased to prevent problems as well.

ninode stands nor number of inodes. Lots of files can go on a single inode.

inodes are disk sections. You can have 100 files open at the same time that happen to set on a single inode.

Hope that helps.

SEP

Re: Changing maxfiles_lim

Geoff Wild — Wed, 06 Feb 2008 17:26:41 GMT

You need to change maxfiles and maxfiles_lim in order to resolve performance issues with file descriptors....

On my oracle servers I have them both set to 4096.

Rgds...Geoff

Re: Changing maxfiles_lim

James R. Ferguson — Wed, 06 Feb 2008 17:32:28 GMT

Hi:

Before you change the value of 'ninode' make sure you read this whitepaper:

http://docs.hp.com/en/7779/commonMisconfig.pdf

Your setting may be appropriate for your configuration and increasing it my simply waste memory.

Regards!

...JRF...

Re: Changing maxfiles_lim

OFC_EDM — Thu, 07 Feb 2008 08:45:44 GMT

Geoffs entry tweeked this question from me.

Anyone know of any articles, forum discussions etc. that discuss resolving performance issues with file descriptors?

I'd like to get more exposure about this issue and what people do to address it.

Re: Changing maxfiles_lim

likid0 — Thu, 07 Feb 2008 13:59:20 GMT

Here you have a good topic, that explains some points:

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=949603&admit=109447626+1202392664157+28353475

Re: Changing maxfiles_lim

James R. Ferguson — Thu, 07 Feb 2008 14:06:57 GMT

Hi (AGAIN):

> Anyone know of any articles, forum discussions etc. that discuss resolving performance issues with file descriptors?

Consider:

Many of the kernel parameters (including those limiting the number of open files) are fences to simply prevent rogue programs from usurping all of a resource.

Fundamental, good programming techniques include closing files when you don't need them.

Regards!

...JRF...