I'm wondering just when it's OK to pull in and out those mobile disk
racks. (Where you can slide in and out one of your PC's IDE hard disks
with "the ease of a floppy"). It seems one should slide one in only
if one plans to reboot. And slide one out only if it has already been
unmounted. Are there any other concerns here on Debian GNU/Linux?

(Wonder if the fan on the rack will hopefully go off when the disk is
out, as it is 99% of the time.)