Solution for NFS4 client showing groups as nobody

I ran into a problem where most of my client servers use NFS3, but my new CentOS 6 client servers use NFS4 to connect to the NFS4/3 shares. The problem was what all NFS files showed file groups as “nobody” on the client servers. Luckily I found a Serverfault post about it and was able to fix it: http://serverfault.com/questions/364613/centos-6-ldap-nfs-file-ownership-is-stuck-on-nobody. Here’s a quick rundown:

Edit the /etc/idmapd.conf file and uncomment the line

#Domain = local.domain.edu

and replace it with the same value as in the NFS server, usually localdomain. You might want to change it to your actual network domain.

I rebooted after that, but it wasn’t enough to make it work since the information is cache. Run the following command to flush the cache.

nfsidmap -c

And that’s it! The groups should now be working.

UPDATE:

Unfortunately I encountered a problem. When doing a chown from the client, it changed the owner to nobody instead of the given user. I was unable to solve this, so I reverted to NFS3. I did it by mounting the shares in /etc/fstab by using the full export path and including the parameter vers=3 in the parameters.

You can check the full export paths from the client with the following command:

shownmount -e servername_or_ip

Hopefully I’ll be able to solve it soon.