Sorry guys, I know this question has been asked and answered 1000 times, but I have been trawling through this forum and others and still haven't managed to solve the problem

I have two servers and a bunch of cluster nodes all using nfs to access files. Both of the servers have multiple nfs exports with the options: (rw,no_root_squash,no_subtree_check). The directories are mounting with version 4 on the cluster nodes.

Both servers have similar hostnames; server1.myschool.edu.au and server2.myschool.edu.au. In the idmapd.conf, I have tried with the domain commented out and with it specified as myschool.edu.au

One of the most bizarre things is that mounts from one server display the correct owners and groups, while mounts from the other server all display nobody:nobody. AFAIK, the configurations are the same, but there must be something causing the difference. The servers are not EXACTLY the same (ie. one is forwarding NAT using iptables), but I do not think this is causing the issue.

Both servers are running stock CentOS 6.5. NFS services, NFS mountd, NFS daemon & RPC idmapd are all running on both machines (and have been restarted)

I am at odds on how to proceed from here, this has been bugging me for a while. Most of the posts I have seen point towards idmapd.conf, but I do not think that is the problem.

Any advice would be greatly appreciated! Happy to provide more info if I have missed anything out.

Stu

On the client, do you set NEED_IDMAPD=yes in /etc/default/nfs-common?

Hi nini, thanks for your reply. The machines do not have /etc/default/nfs-common. In fact, /etc/default only has useradd and nss. Should I create this file in there?

Initially, I thought the issue must be server-side because the same clients can connect to the other server and show the correct UID/GIDs; therefore I thought the clients were fine.

Thanks,

Stu

Yes, create the file. Try following things on client.
Edited /etc/idmapd.conf and set domain on server and client to be the same.
Created an /etc/default/nfs-common file and added "NEED_IDMAPD= yes" to that file.

Note: Different server could return different thing.