So I went to edit this page, discovered it didn't exist, and got this:
Three things are certain:
Death, taxes and lost data.
Guess which has occurred.
So you've got a bunch of processes waiting on disk because the device mounts on /home is hosed, and you know you can fix it, if you could just umount the f&^%ing thing. Now unless /home is NFS mounted (in which case you've probably got more than one machine with this problem, you poor bastard) with intr, you're probably screwed without a reboot.
But you can't reboot, right? You can't sync, or kill the processes waiting waiting on disk (cause, well, they're waiting on disk), or whatever, because the device is poked.
Well, apparently the cunning folks that invented reboot (or halt, take your pick), have thought of this, and added the -n (don't sync before reboot/halt) and -f (do it now, really) options. So try your luck with reboot -ns (might want to comment out the /home line in fstab first, presumably the whole reason you're trying to force a reboot without hitting the reset button is because the machine's a long way away, and having it die on reboot because it can't mount the hosed /home media is not going to be a good look).
Danger Will Robinson, data loss may occur, etc, etc. Not my fault.