NFS: Problem with user and group IDs

NFS: Problem with user and group IDs

[Thomas Babut]

Hi,

I've got a problem with 'squashing' user and group IDs under NFS.

On the NFS Server there is the directory /data/test with owner ID 1011 
and group ID 100.

Here is the /etc/exports file on the NFS server:
/data/test 
172.16.10.1(ro,root_squash,all_squash,anon_uid=65534,anongid=65534)

On the client side I mount it with the command:
mount -t nfs 172.16.10.2:/data/test /mnt/test

After it has been successfully mounted, the directory on the client 
system has the owner ID 1011 and group ID 100, like on the server.

But the expected result for me is, that on the client system the 
directory has owner ID 65534 and group ID 65534 like it has been set in 
the /etc/exports file on the server.
I tried less options in the exports file as well. The result is always 
the same. With squash and without squash options.

Client and Server are Debian woody. I tried this on a Debian sid 
(unstable) system as well, same results. Switching from 
nfs-kernel-server to nfs-user-server didn't change anything, too.

My question is now: Is this a bug, or I am doing something wrong?

Thanks for any answer.

Regards,
Thomas Babut

Re: NFS: Problem with user and group IDs

[J. Bruce Fields]

On Tue, Jun 01, 2004 at 04:58:03PM +0200, Thomas Babut wrote:
> I've got a problem with 'squashing' user and group IDs under NFS.
> 
> On the NFS Server there is the directory /data/test with owner ID 1011 
> and group ID 100.
> 
> Here is the /etc/exports file on the NFS server:
> /data/test 
> 172.16.10.1(ro,root_squash,all_squash,anon_uid=65534,anongid=65534)
> 
> On the client side I mount it with the command:
> mount -t nfs 172.16.10.2:/data/test /mnt/test
> 
> After it has been successfully mounted, the directory on the client 
> system has the owner ID 1011 and group ID 100, like on the server.
> 
> But the expected result for me is, that on the client system the 
> directory has owner ID 65534 and group ID 65534 like it has been set in 
> the /etc/exports file on the server.

Root-squashing only modifies the way your client credentials are seen on
the server; it isn't applied to uid's that are returned to the client
e.g.  when listing a directory.  So if you create a new file as a user
on the client, that new file will be given anonymous uid and gid.  But
if you "ls" a directory, the uid's you see will be unaffected by
squashing.

--Bruce Fields