<< Ubuntu | Journals | Courier IMAP Fixing Script >>
The Link
See https://help.ubuntu.com/6.06/ubuntu/serverguide/C/network-file-system.html
Warning Ubuntu 7.01
If you mount an NFS drive and somehow disconnect the NFS server either by shutting down or physically removing the connection, all the other mounted drives may hang. You are also unable to umount /nfsdrive, it will say that the device is busy. You might try sudo fuser -m /nfsdrive to see if who is using it and kill the process, that I might try next. But what I did was to re-connect before unmounting.