[Lustre-discuss] filesystem UID' GID's

[D. Marc Stearman]

On Apr 11, 2008, at 6:07 AM, Jakob Goldbach wrote:
>
> On Fri, 2008-04-11 at 09:01 -0400, Brock Palen wrote:
>> Does a /etc/passwd with all the filesystem users UID's required only
>> on the MDS ?  Or does the OST's need them also?
>
> MDS only. But this is not needed either if you
>
> mds# echo NONE >  proc/fs/lustre/mds/<fsname>-MDT0000/group_upcall
>
> Then you only need uid/gid to be available on all clients.
>
> /Jakob

Jakob is correct.  The group_upcall is needed if you want to support  
large numbers of secondary groups.  We have users at LLNL that belong  
to >16 groups, and the group_upcall is needed to support permissions  
access with all those groups.  I think by default lustre will only  
check the first two groups you belong to.

If your users don't use additional groups, then you can do as Jakob  
suggested.

-Marc

----
D. Marc Stearman
LC Lustre Administration Lead
marc at llnl.gov
925.423.9670
Pager: 1.888.203.0641