Steve Fosdick lists@pelvoux.nildram.co.uk wrote:

You may have read in another thread that I now have a NAS. The NAS supports NFS so it seemed completely natural to NFS mount a directory tree from the NAS on a desktop PC and to put this mount in the /etc/fstab file so it is mounted whenever the desktop PC is started. I did this and specified the 'bg' option so that if the file system concerned is not available the mount is retried in the background.

Upon the next reboot of the PC it got stuck in the boot process in such a way that all I could see was the Ubuntu logo and no text. Using the Ctrl-Alt combinations to switch virtual console did not make any difference (no text appeared) and Ctrl-Alt-Backspace to kill a running X server did not make any difference either. In the end I used the magic SysReq to reboot the PC.

Upon choosing the "recovery mode" from GRUB I found that the NFS mount was not working because the network card was not up. It seems that when you use the helpful GNOME-based network configuration to configure a network connection it then does not get started early enough in the boot process to support the NFS mount which is rather different than if it had been configured in the /etc/network/interfaces file.

I had a very similar issue with my studio machine connecting to the NAS in the house using NFS over a longish ethernet string (~50m). In my case I had used /etc/network/interfaces to permanently configure the network card, and all worked well with 8.04. Upgrading to 9.10 late last year and switching to 'upstart' caused the NFS mount to fail sometimes on startup.

Further investigation of the 'upstart' configuration (in /etc/init/*) indicated that there was a race condition between the 'mountall' process and the networking startup: if the network came up quickly enough (which varies a bit depending on the rain and DHCP server response speed :) all was well; if the network init was a bit slow, then mountall would be stopped by the rcS event or exit of it's own accord and nothing would mount the NFS when the network did come up. I fixed this by the rather ugly hack of modifying the mountall-net.conf script to directly call mount on my NFS if it was unable to find mountall running.

There are other similar problems it seems with upstart and NFS: https://bugs.launchpad.net/ubuntu/+source/mountall/+bug/501678 https://bugs.launchpad.net/ubuntu/+source/mountall/+bug/430348

Phil.