Comment 10 for bug 234480

This can be fixed by not using a hardmount in /etc/fstab. If you add the "soft" option to your mount parameters, the filesystem remains active. I think this is expected behavior for NFS (hard is default due to possible instability issues with soft mounting).

From man nfs:

      soft / hard Determines the recovery behavior of the NFS client after
                     an NFS request times out. If neither option is speci-
                     fied (or if the hard option is specified), NFS requests
                     are retried indefinitely. If the soft option is speci-
                     fied, then the NFS client fails an NFS request after
                     retrans retransmissions have been sent, causing the NFS
                     client to return an error to the calling application.

                     NB: A so-called "soft" timeout can cause silent data
                     corruption in certain cases. As such, use the soft
                     option only when client responsiveness is more important
                     than data integrity. Using NFS over TCP or increasing
                     the value of the retrans option may mitigate some of the
                     risks of using the soft option.