You may configure your hosts to utilize a Network Attached Storage (NAS) over NFS for virtual machine storage. By using NAS storage your hosts can be completely diskless.
In the WebApp, select the Storage tab on a host server. Then click Add NFS.
In the Path field enter:
-t nfs -o rw,nfsvers=3 192.168.0.2:/exports/hypervisor1
Where “192.168.0.2” is the IP number of your NFS server or NAS and “/exports/hypervisor1″ is the path to the NFS export dedicated to this particular host.
Then click the Add button to mount the remote storage.
Last, you may want to review the logs to see that everything looks okay. Also double check that the free disk space on the server match the NAS/NFS storage, to be verify the mount is okay.