I may have misrepresented it: they may have been able to be parked, but that required a controlled shutdown - not a sudden hardware failure. And these were supercomputers, before cheap commodity hardware took over server rooms. It was common that these would be turned on and almost never be shut off except when being replaced.
Lots of hard drives required parking and would risk running the drive if the heads weren’t parked before being spun down. The design required the later of air from the spinning disks to float the heads over the disks - if you didn’t park the heads before spinning them down, the heads would touch down on the disks, sometimes while there were still spinning, and scratch the surface and ruin the disk.
I may have misrepresented it: they may have been able to be parked, but that required a controlled shutdown - not a sudden hardware failure. And these were supercomputers, before cheap commodity hardware took over server rooms. It was common that these would be turned on and almost never be shut off except when being replaced.
Lots of hard drives required parking and would risk running the drive if the heads weren’t parked before being spun down. The design required the later of air from the spinning disks to float the heads over the disks - if you didn’t park the heads before spinning them down, the heads would touch down on the disks, sometimes while there were still spinning, and scratch the surface and ruin the disk.