@vmpr Great work and example!
@vmpr Not much, this is a system issue which means that it's either due to your NFS server or to the connection between your XO and the NFS server.
First, try to unmount the share and restart xo-server, if it keeps happening, restart the whole machine on which XO is.
If that does not help, you should mount the share manually and do some tests directly on it.
@vmpr Please create an issue on Xen Orchestra GitHub repo, this way XO dev will see it 🙂