[ic] IC setup in Multi permission mode - sort of off topic

Kevin Walsh interchange-users@interchange.redhat.com
Mon Nov 5 15:52:01 2001


> Ok this isn't particular to IC per say, but I didn't find a quick answer
> to this anywhere else, including all the support forums at Redhat.
> 
> We started running IC under Redhat 7.2, and I almost immediately ran into
> hard coded limitations on the number of groups that a process can belong
> to. The default is 32, pretty low if you ask me but oh well...  Ok so
> anyways I modified NGROUPS and NGROUPS_MAX in limits.h and
> param.h, recompiled, not it...  Do I have to rebuild glibc also?  What am
> I missing?
>
You would have to rebuild the kernel, the C compiler, any other
compilers you have, C libraries etc., possibly Perl and some Perl
modules, applications and a bunch of other stuff I haven't thought
of.

Once you have done all this, you will find that NGROUPS is used
all over the kernel and are left with the question "what is going
to break now that I've changed this?"  NFS?

Some people have set NGROUPS_MAX to 256 without any trouble, others
have not.  I have no need for anywhere near 32 group memberships per
user so I haven't looked into the implications at all.  Give it a go
if you feel brave.

Good luck.

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