fb was requiring manual fsck on it's disks because it was sensing filesystem errors.  The errors had to do with the filesystem timestamps being in the future.  It turned out that fb's system date was set to something in 2005.  I'm not sure what caused the date to be so off (motherboard battery problem?)  But I did determine after I got the system booting that the NTP client on fb was misconfigured and was therefore incapable of setting the system date.  It seems that it was configured to query a non-existent ntp server.  Why the hell it would have been set like this I have no idea.

In any event, I did a manual check on /dev/sdb1, which is the root disk, and postponed a check on /dev/sda1 (the RAID mounted at /frames) until I had the system booting.  /dev/sda1 is being checked now, since there are filesystems errors that need to be corrected, but it will probably take a couple of hours to complete.  Once the filesystems are clean I'll reboot fb and try to get everything up and running again.