In preparation for Y2K, we had to turn off our text archive server (at a newspaper) for the first time in, literally, years. The machine itself has been in production for six years, the last two or so of which without a reboot.
It was an IBM AIX machine with an array of 4.5GB SCSI drives. After sitting with its power off for a couple hours, we turned it back on and Nothing Happened. No drives were spinning. Crap.
Called IBM tech support. Got the run-around. Finally got to a guy who said something along the lines of "you're going to think this is crazy but do what I say in this order" followed by...
* turn machine off
* remove drives
* turn the machine on
* bang the drives on their edge a few times on the floor - don't go crazy but harder than you think is a good idea
* spin the drives flat on the ground as though they were tops
* immediately, put the drives in the enclosure
* reboot the machine but do not power it off
Damn if the guy wasn't right.
His guess was that the drives had been powered for eight or so years and the lubricant had either broken down or the heads were simply stuck to the platters. The thumping dislodged the heads and the spin gave the grease a fighting chance. {shrug}
In any case, we dared not turn it off for another year and a half until at such time it was replaced. We thought about buying replacement drives but IBM wanted something along the lines of $600 for a 4.5GB drive. Even on eBay, they were three times what we felt was reasonable.
Cheers,
Matt