It’s been a long time since I administered NFS filesystems, so please excuse any stale/inaccurate information I’m about to provide. There are two sides to mounting NFS volumes, the NFS server and client. The NFS server exports the volumes it finds in /etc/exports and the clients mount them from the server. The specific property you are interested is suid/nosuid. I don’t recall if there are options on the server side that need to be configured to enable suid, but I know the suid option need to be passed to the mount command on the client. You should be aware that there are security concerns with allowing SUID programs on NFS volumes. Those are the relevant keywords to search for with you favorite search engine.
That’s also the reason you see PBS complaining. The pbs_iff program needs to be installed as SUID. It’s likely that it is (you should check the permissions on it), but NFS is preventing it from working properly.
-sh-4.2$ ls -l /opt/pbs/sbin/pbs_iff
-rwsr-xr-x 1 root root 218528 Jan 15 11:53 /opt/pbs/sbin/pbs_iff
Note the “s” in the fourth character above that indicates the SUID flag has been enabled for that file. You may already know most of this, but I don’t know your level of experience. Hope that helps.