> You can set the sleep time in the firmware of most drives, although some
> respond better than others. I've been able to set the sleep time in WD
> drives but not Seagate, but both go to sleep when instructed.
FWIW, the `hdparm -S` doesn't really work for WD drives last I checked.
More specifically, IIUC WD drives will mostly disregard the "time to spin
down" you specify and instead they'll use their own idea of what the
time to spin down should be based on the power-management level
you specified.
Stefan
