Hi Rainer,
When the external disk is mounted, it does not go into standby/sleep/whatever, though I'm using it only for 30minutes at night.
Is there a way to do this with C4, 2.6.9-78.0.8.ELsmp? E.g. unmount/some special command/upgrade to 5.2?
man sg_start (part of the sg3_utils package). For a Western Digital MyBook I use: sg_start 0 --pc=3 /dev/sda
Chris