SUN: Max groups/user circumventionΒΆ

Title:SUN: Max groups/user circumvention
Author:Douglas O’Leary <dkoleary@olearycomputers.com>
Description:SUN: Max groups/user circumvention
Date created:08/2001
Date updated:09/2001
Disclaimer:Standard: Use the information that follows at your own risk. If you screw up a system, don’t blame it on me...

This ll courtesy of Steve Costaras

SUN apparently has maximum users/group setting of 16 built into the kernel. I seem to remember hearing about this on other systems, but specifics escape me at the moment. Apparently, users cannot take advantage of group permissions after the 16th group.

To get around this there is a kernel parameter called ngroups_max which you can up to 32 from it’s default of 16.

you can check what your current setting is by:

adb -k /dev/ksyms /dev/mem
ngroups_max/D
^D (to exit)

This will display your current setting on a running system. Just up it in /etc/system.

There is one side-affect that I’ve noticed. NFS v2. It appears that at least some implementations of NFS v2 also limit you to 16 groups/user. I don’t know about NFS v3.