topic Re: Kernel Parameter Question !! in Operating System - HP-UX

Kernel Parameter Question !!

rveri — Wed, 25 May 2005 14:18:29 GMT

Hi All ,

Can anyone tell ,

What is the parameter that defines how many files OS will allow to be opened simultaniously, and how to know its value.

I hv checked # mktune | grep -i max , its givning maxfiles and maxfiles_lim , does this are the parameters related to that. And its confusing , which one for what.?

Appriciate ,If any one can explain .

Thank you,
R.Veri.

Re: Kernel Parameter Question !!

Robert Salter — Wed, 25 May 2005 15:23:43 GMT

rveri,

Read this: http://www.docs.hp.com/en/TKP-90202/ch05s03.html

I'm having problems replying, hope you get this.

Re: Kernel Parameter Question !!

RAC_1 — Wed, 25 May 2005 15:25:25 GMT

nfile is system wide open files limit. maxfiles and maxfiles_lim are soft and hard limits for user processes.

Anil

Re: Kernel Parameter Question !!

A. Clay Stephenson — Wed, 25 May 2005 15:28:40 GMT

The answer is neither. The system-wide limit is determined by 'nfile'; maxfiles and maxfiles_lim determine the soft and hard (respectively) per process file limits.

Re: Kernel Parameter Question !!

Robert Bennett_3 — Wed, 25 May 2005 15:31:56 GMT

Check out this cookbook:

http://www.peoplesoft-hp.com/salestools/whitepapers/%5Bfiles%5D/Technical/HPUX%20Performance%20Cookbook.pdf

I always refer to this - easy reading for a difficult subject.

Also check these kernel parms: maxuprc, maxusers, nfile and nproc.

Had trouble getting this in - hope it helps.

B

Re: Kernel Parameter Question !!

TwoProc — Wed, 25 May 2005 15:34:59 GMT

maxfiles is the soft file limit per process.
maxfiles_lim is the hard file limit process.
nfile is the OS limit for number of open files.

pay attention also to the following as they will somewhat scale the above relevant to the items below - meaning, that in general if you're raising the above numbers, then these below will need review also.

nflocks is the OS limit for number of open file locks.
nproc - max number of processes.
maxuprc - max number of user processes.

Re: Kernel Parameter Question !!

Patrick Wallek — Wed, 25 May 2005 15:42:01 GMT

There are 3 parameters nfile, maxfiles, maxfiles_lim.

There is documentation about kernel parameters here:

PDF File: http://docs.hp.com/en/TKP-90202/TKP-90202.pdf

HTML: http://docs.hp.com/en/TKP-90202/index.html

nfile - Max. number of open files for the entire system.

maxfiles - Soft limit on how many files a single process can have opened or locked at any given time.

maxfiles_lim - Hard limit on how many files a single process can have opened or locked at any given time

If you are on HP-UX 11.11, then do a 'man 5 kernel_parm_name'

# man 5 nfile
# man 5 maxfiles
# man 5 maxfiles_lim

Re: Kernel Parameter Question !!

harry d brown jr — Thu, 26 May 2005 06:13:07 GMT

This is what I tried posting yesterday :-)

Go into sam->kernel configuration->configurable parameters->help-> configuratble kernel parameters

or read this:

Mass-Storage Subsystem

* Overview of File System Kernel Parameters
* Configurable File System Buffer-Cache Parameters:

bufpages Pages of static buffer cache
dbc_min_pct Minimum dynamic buffer cache
dbc_max_pct Maximum dynamic buffer cache
nbuf Number of static buffer headers

* Configurable Open or Locked Files Parameters:

maxfiles soft limit for open files
maxfiles_lim hard limit for open files
nfile system-wide open-files limit
nflocks system-wide file-lock limit
ninode Maximum open inodes in memory

* Configurable Asynchronous Write Parameter:

fs_async Enable/disable asynchronous disk writes

* Configurable VxFS (Journaled) File-System Parameter:

vx_ncsize Memory space reserved for VxFS directory path-name cache

live free or die
harry d brown jr