The server has three external SCSI drives, in Sun enclosures. The cat's ass back in the day.
The UPSs (several) have bad batteries. We had a power glitch, the server restarted but one of the external enclosures' fans didn't start. It overheated and the SCSI chain ground to a halt. Auto-reboot wouldn't help, because the enclosure stayed hot.
I've done the bare minimum to get it up again, but I will need to tear the fan apart, clean & lube it (or solder in a new fan). I have spare HDDs but no spare Sun enclosures. Realistically, I should invest in newer storage hardware, but definitely not this month!
Anyway, as I type this, it appears to be OK. As I drive 63 miles away . . .