I just installed OMV 0.5.0.24 and upgraded it to 0.5.0.31. The goal was to use this machine as an NFS store for VMWare guests, sometimes I need some spare space to move machines.
VMWare with version 5.1 still supports NFS V3 shares only, but OMV with version 0.5 presents NFS V4 out of the box. When I try to mount such an NFS share I receive an error like "Unable to connect, NFS V3 share not found".
rpcinfo -p | grep nfs shows that V2, V3 and V4 are present, but the share generated by the web interface is of V4 type.
After some googling I found the solution:
This seems to be a small bug in the /etc/init.d/nfs-kernel-server startup script. There's a line like this:
$PREFIX/bin/rpcinfo -u localhost nfs 3 >/dev/null 2>&1
RPCMOUNTDOPTS="$RPCMOUNTDOPTS --no-nfs-version 3"
The script looks for a NFS V3 connection over UDP (Parameter -u) and if it does not find it it disables NFS V3.
Solution:
Just a small change, replace the -u with a -t (Parameter: TCP connection), restart the NFS server (/etc/init.d/nfs-kernel-server restart) and voila, VMWare can connect to this NFS share and mount it as a datastore.
Even after a reboot the share is accessible and can be mounted on other ESXi hosts.
./edit: Typo corrected.