Everything seems to be back up and running.
The computers weren't such a big problem (or at least didn't seem to be). I turned off the watchdogs, and remotely rebooted all of the computers (except for c1lsc, which Manasa already had gotten working). After this, I also ssh-ed to c1lsc and restarted all of the models, since half of them froze or something while the other computers were being power cycled.
However, this power cycling somehow completely screwed up the vertex suspensions. The MC suspensions were fine, and SRM was fine, but the ITMs, BS and PRM were not damping. To get them to kind of damp rather than ring up, we had to flip the signs on the pos and pit gains. Also, we were a little suspicious of potential channel-hopping, since touching one optic was occasionally time-coincident with another optic ringing up. So, no hard evidence on the channel hopping, but suspicions.
Anyhow, at some point I was concerned about the suspension slow computer, since the watchdogs weren't tripping even though the osem sensor rmses were well over the thresholds, so I keyed that crate. After this, the watchdogs tripped as expected when we enabled damping but the RMS was higher than the threshold.
I eventually remotely rebooted c1sus again. This totally fixed everything. We put all of the local damping gains back to the values that we found them (in particular, undoing our sign flips), and everything seems good again. I don't know what happened, but we're back online now.
Q notes that the bounce mode for at least ITMX (haven't checked the others) is rung up. We should check if it is starting to go down in a few hours.
Also, the FSS slow servo was not running, we restarted it on op340m.