Re: NFS drive uids/gids completely broken- for a little while

[<briand@aracnet.com>]

On Wed, 27 May 2015 13:31:52 -0600
Bob Proulx <bob@proulx.com> wrote:

> briand@aracnet.com wrote:
> > This is a weird one.
> 
> That is a little weird that it was a transient glitch of a failure.
> 
> > Tried to use ssh and saw a "bad permissions" error on my .ssh/config file.
> > 
> > I do ls -l and i see uids/gids of 2^32-1 or a similar very large integer.
> > 
> > WTF ?!
> 
> Are you using --manage-gids?
> 
>   root@fs:~# grep manage-gids /etc/default/nfs-kernel-server 
>   RPCMOUNTDOPTS=--manage-gids
> 
>   $ man rpc.mountd
> 
>    -g  or  --manage-gids
>       Accept requests from the kernel to map user id numbers into
>       lists of group id numbers for use in access control.  An NFS
>       request will normally (except when using Kerberos or other
>       cryptographic authentication) contains a user-id and a list of
>       group-ids.  Due to a limitation in the NFS protocol, at most 16
>       groups ids can be listed.  If you use the -g flag, then the list
>       of group ids received from the client will be replaced by a list
>       of group ids determined by an appropriate lookup on the
>       server. Note that the 'primary' group id is not affected so a
>       newgroup command on the client will still be effective.  This
>       function requires a Linux Kernel with version at least 2.6.21.
> 
> That is normal for an NIS/yp environment.  But it means that uid
> lookups are done over the network.  A transient network would return
> -1 error codes for all of the numbers.  It will make user ids appear
> to be -1.
> 

aha. sounds like my problem. interesting that it's enabled by default.

i'm assuming that for my rinky-dink set-up with 5 users i don't need it ?



Brian