We recently added 2 hypervisors to the domain on ovirt, but for some reason they can't connect to the nfs share:
When I manually try to mount the nfs-share ([root@ovirthyp01dev ~]# mount -vvv -t nfs -o vers=3,tcp progress:/media/NfsProgress /rhev/data-center/mnt/progress.brusselsairport.aero\:_media_NfsProgress/)
:
mount: external mount: argv[3] = "-v"
mount: external mount: argv[4] = "-o"
mount: external mount: argv[5] = "rw,vers=3,tcp"
mount.nfs: timeout set for Tue Dec 16 08:56:47 2014
mount.nfs: trying text-based options 'vers=3,tcp,addr=10.110.56.20'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: portmap query failed: RPC: Program not registered
mount.nfs: requested NFS version or transport protocol is not supported

From vdsm.log:
Thread-277::ERROR::2014-12-16 08:46:32,504::storageServer::211::Storage.StorageServer.MountConnection::(connect) Mount failed: (32, ';mount.nfs: requested NFS version or transport protocol is not supported\n')
Traceback (most recent call last):
  File "/usr/share/vdsm/storage/storageServer.py", line 209, in connect
    self._mount.mount(self.options, self._vfsType)
  File "/usr/share/vdsm/storage/mount.py", line 223, in mount
    return self._runcmd(cmd, timeout)
  File "/usr/share/vdsm/storage/mount.py", line 239, in _runcmd
    raise MountError(rc, ";".join((out, err)))
MountError: (32, ';mount.nfs: requested NFS version or transport protocol is not supported\n')
Thread-277::ERROR::2014-12-16 08:46:32,508::hsm::2433::Storage.HSM::(connectStorageServer) Could not connect to storageServer
Traceback (most recent call last):
  File "/usr/share/vdsm/storage/hsm.py", line 2430, in connectStorageServer
    conObj.connect()
  File "/usr/share/vdsm/storage/storageServer.py", line 328, in connect
    return self._mountCon.connect()
  File "/usr/share/vdsm/storage/storageServer.py", line 217, in connect
    raise e
MountError: (32, ';mount.nfs: requested NFS version or transport protocol is not supported\n')