So, I did a bad sector check in the SCSI BIOS (Adaptec's SCSI chipsets are awesome), and the check found one bad sector on the 9Gb Fujitsu disk, which I told it to remap. The machine seems to be fine now, but bad sectors are indicative of pending drive failure. So, I'm going to have to come up with a long-term solution to this problem. For the time being, I have resurrected my old 4.5Gb IBM U2W SCSI disk, and slapped that in redefine. I've setup a cron that rsync's the relevant bits from the 9Gb disk over to the 4.5Gb, so I can boot off of that in an emergency. But I think that going forward, I need to come up with some sort of RAID solution, so that this machine can drop a disk, and I can wait until the weekend in order to deal with it.
But this caps a "bad computer day" for me. Not only did redefine have some issues, but towards the end of my work day today, a server that I was working on went south. A co-worker was doing a package install at the time, and we suspect that the package had something like "rm -rf $INSTALL_LOC/" in a post-install script. Of course, if the "$INSTALL_LOC" variable is null, then the shell will translate that command to "rm -rf /", which on any UNIX box (and Solaris in particular) is quite a bad thing to do.