topic Re: Software and hardware limits in Operating System - HP-UX

Software and hardware limits

Shivkumar — Wed, 13 Jul 2005 11:29:31 GMT

Dear Sirs,

Is there a rule that hardware limit(maxfiles_lim) is always greater than or equal to the software limit (maxfiles) ?

Below is the rule i saw :

nfile (maxfiles <= maxfiles_lim <= nfile/2).

In case maxfiles_lim is less than maxfiles what would be the impact ? Will it cause lower system performance ?
This is on hpux 11/11i.

Thanks,
Shiv

Re: Software and hardware limits

Mel Burslan — Wed, 13 Jul 2005 11:44:21 GMT

With my limited knowledge of kernal internals, maxfiles_lim is the absolute maximum number of files that can be open, a.k.a., hard limit and maxfiles is the soft limit which can be expanded until the number hits maxfiles_lim under certain conditions.

If you try to set maxfiles_lim smaller than maxfiles, and do it via sam, you will see a error screen which will not let you do that. If you want to manually compile a kernel, I am not 100% sure but compile may abort with errors. In an abnormal case that it goes and compiles it, I would not trust that kernel anyway. Setting the values this way is logically wrong in my opinion.

Re: Software and hardware limits

Robert-Jan Goossens — Wed, 13 Jul 2005 11:48:23 GMT

Shiv,

Check this docs

Document description: Why is maxfiles_lim set below maxfiles?
Document id: UPERFKBQA00000518

US
http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000077186736

Europe
http://www4.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000077186736

Regards,
Robert-Jan

Re: Software and hardware limits

Cem Tugrul — Wed, 13 Jul 2005 23:23:50 GMT

Shiv,

As an addition to other replies another
guide doc from me.Take a look of my attachment...
Good Luck,