Comment 3 for bug 974374

We just had a similar incident.
The local server autofs mounts a remote NFS. The remote server unexpectidly powered off (no normal shutdown). The remote server was powered back on however the local server was not able to access the remote NFS's. It appears the local server never umounted the remote NFS's. When you did and ls -l a bunch of question marks would appear. We attempted umount the remote mounts but the local server kept saying: {mount} was not found in /proc/mounts.

root@mysql02:/etc# df

Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/mysql02-root 716514760 11255404 668862508 2% /
udev 6143968 4 6143964 1% /dev
tmpfs 2461300 516 2460784 1% /run
none 5120 0 5120 0% /run/lock
none 6153244 0 6153244 0% /run/shm
/dev/sdg1 233191 98407 122343 45% /boot
/dev/md0 3845737480 590404808 3059980404 17% /d01
logilive:/opt/logisoft 816146560 176438624 597581376 23% /net/logilive/opt/logisoft
lwt1:/opt/logisoft 24520704 11627520 11646976 50% /net/lwt1/opt/logisoft

root@mysql02:/etc# umount /net/logilive/opt/logisoft

/net/logilive/opt/logisoft was not found in /proc/mounts
/net/logilive/opt/logisoft was not found in /proc/mounts

we could never get the local server to umount the remote server. We had to reboot the local server.