topic Re: No more free slots in kernel's process-table error. in Operating System - HP-UX

No more free slots in kernel's process-table error.

Gino Castoldi_2 — Wed, 10 Dec 2003 14:00:42 GMT

Hi,

HP-UX 11.0 L2000 OVO 6.14 NNM 6.2 Oracle 8.1.7.3 4GB Memory.

We received these messages a short while ago.
What kernel parameters do we need to adjust to
resolve this problem?

"fork(2) failed; no more free slot in kernel's process-table - Resource temporarily unavailable (OpC20-412)"

/var/adm/syslog/syslog.log:
Dec 6 11:37:54 vmunix: file: table is full
Dec 6 11:37:55 inetd[797]: hacl-cfg/tcp: accept: File table overflow
Dec 6 11:39:18 vmunix: proc: table is full

10 points to any good answer.
Thank you
Gino

Re: No more free slots in kernel's process-table error.

Pete Randall — Wed, 10 Dec 2003 14:02:15 GMT

Gino,

nproc

Pete

Re: No more free slots in kernel's process-table error.

A. Clay Stephenson — Wed, 10 Dec 2003 14:02:48 GMT

Nproc and nfile need increasing.

Re: No more free slots in kernel's process-table error.

Pete Randall — Wed, 10 Dec 2003 14:02:53 GMT

Possibly nfiles, too.

Pete

Re: No more free slots in kernel's process-table error.

Jeff Schussele — Wed, 10 Dec 2003 14:03:40 GMT

Hi Gino,

Or maxuprc

Rgds,
Jeff

Re: No more free slots in kernel's process-table error.

RAC_1 — Wed, 10 Dec 2003 14:13:23 GMT

Kernel parameters

nfile
nproc
maxuprc
nflocks

Re: No more free slots in kernel's process-table error.

Steven E. Protter — Wed, 10 Dec 2003 14:18:02 GMT

I'm late.

I don't need points.

I'm attaching a script that will collect data nd allow you to spot any kernel parameters that are being stressed out.

I think the list is pretty complete here, but I find that a little pit of analysis will make sure that you don't have to fiddle with the kernel three or four times and reboot the machine.

See attachment.

SEP

Re: No more free slots in kernel's process-table error.

Gino Castoldi_2 — Wed, 10 Dec 2003 14:20:25 GMT

Hi,

Any recommendations as to what values
that I should set the kernel to?

10 points to any good answer.
Thank you
Gino

Re: No more free slots in kernel's process-table error.

jerry1 — Wed, 10 Dec 2003 17:12:19 GMT

Start with number of users and/or processes you expect to have on the system since the kernel parameter

nproc = ((20+8*MAXUSERS)+500)

and then nproc is then used in other kernel
params in the same way. Check out the formulas and you can get an idea of what might change by changing on param.

Use:

sysdef -to get kernel params ranges.
kmtune -to get the kernel params with formulas.

There is no easy way to determine what the best settings should be. It depends on what you entend to run on the system and the resources available on the system. Some params are dynamic now with 11i and do not require changing.

Re: No more free slots in kernel's process-table error.

Con O'Kelly — Wed, 10 Dec 2003 19:43:25 GMT

Hi Gino

Check the current value of your 'maxusers' kernel parameter (kmtune -lq maxusers). This parameter is normally used to size the nproc & nfile parameters. I normally set maxusers to about 200 (which also sizes nproc & nfile), however it does depend on what your system is doing. Also note that some systems are setup with hardcoded values for nproc & nfile, rather than using a formulae.

Once you have increased the value, you can check the file & proc table utilisation using:
# sar -v 2 5

I normally like to see the the file & proc table utilisation at about 70%-80%. If you're proc or file table utilisation is consistently above 90% then I'd look at increasing the value of nproc & nfile further.
If you are collecting sar data you can check back through the sar data and get an idea of your proc & file table utilisation over the last few weeks.

The Kernel Tuning Guide by Stephen Ciullo provides excellent advice on tuning kernel params:
http://docs.hp.com/hpux/onlinedocs/os/11.0/tuningwp.html

Cheers
Con