When I came in earlier today, I noticed that c1susvme2 was red on the DAQ screens. Since the vme computers always seem to be happier as a set, I hit the physical reset buttons on sosvme, susvme1 and susvme2. I then did the telnet or ssh in as appropriate for each computer in turn. sosvme and susvme1 came back just fine. However, I couldn't cd to /cvs/cds/caltech/target/c1susvme2 while ssh-ed in to susvme2. I could cd to /cvs/cds, and then did an ls, and it came back totally blank. There was nothing at all in the folder.
Yoichi showed me how to do 'df' to figure out what filesystems are mounted, and it looked as though the filesystem was mounted. But then Yoichi tried to unmount the filesystem, and it claimed that it wasn't mounted at all. We then remounted the filesystem, and things were good again. I was able to continue the regular restart procedure, and the computer is back up again.
Recap: c1susvme2 mysteriously got unmounted from /cvs/cds! But it's back, and the computers are all good again.