I saw a file with a bad inode, so I have the system in a maintenance mode, and I'm running fsck.
I'll have it back up in 10 minutes...
Hmmm - 30 seconds after I gave the last command to bring everything back up, my connection got dropped...
Ahhh - looks like I should have rebooted rather than just remounting - the system panicked and rebooted on it's own.
Everything looks fine now.