SUMMARY: Increasing number of processes ?

From: Wilkinson,Alex <>
Date: Wed May 08 2002 - 22:11:34 EDT
Thanks to
scotrn <>
amit mahajan <>
Mike's List <>
Wolf Schaefer <>

Original Question

I have a problem where one user of a group I belong to spawned a lot of processes
without killing them. When I tried to log in and vfork reported a failure
(No process available). I logged in as root and rebooted the machine.

Is there any way to increase the number of processes (PID)
available to a group of users?

System is:

Sun Os 5.5 Generic_103093-27 sun4m sparc, SPARC, CPU-5V


You probably want to look at three tunables.  In short order.

max_nprocs:  derived as 10+(16 x maxusers)
maxusers: see above.  Affects many other tunables, however.
reserved_procs: numbers of reserved processes that can run in the process
table, only as UID 0.  Defaults to 5, I ususally run the box, ps -ef and
grep for UID 0/root processes, add 10 and change in /etc/system in the
event of just such an issue you experience. :)


The maxusers kernel parameter is the one most often tuned. By default, it is
set to the number of Mb of physical memory or 1024, whichever is lower. It
cannot be set higher than 2048.
Several kernel parameters are set when maxusers is set unless otherwise
overridden by the /etc/system file. Some of these formulas differ between
different versions of Solaris:

max_nprocs: Number of processes = 10 + (16 x maxusers)

ufs_ninode: Inode cache size = (17xmaxusers)+90 (Solaris 2.5.1) or
4x(maxusers + max_nprocs)+320 (Solaris 2.6-8).

ncsize: Name lookup cache size = (17xmaxusers)+90 (Solaris 2.5.1) or
4x(maxusers + max_nprocs)+320 (Solaris 2.6-8).

ndquot: Quota table size = (maxusers x 10) + max_nprocs

maxuproc: User process limit = max_nprocs - 5


I think you can edit /etc/system and have the following line:
set pt_cnt=256
set maxusers=64

Not sure if you need both or not, but you can try it and see...

/etc/system = the kernel, so you'll have to reboot, might want
to search the archive first (not
and and


Add the following line to your /etc/system file and reboot with
option -r.  From the ok prompt boot -r, from the UNIX command
line reboot -- -r.

set pt_cnt=127



 - Alex
sunmanagers mailing list
Received on Wed May 8 22:28:24 2002

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