I don't know if this is a bug but I wasn't sure where else to post it.
I have two spindown problems in RC2:
I've set default spindown to 15 minutes to help with testing.
(1) The USB disk in Unassigned devices
Unraid tries to spin it down (good!) but doesn't actually do it. That may be a problem with the drive's USB interface so I've cron'd a user script to spin it down with hdparm -y /dev/sdb (which works.) It looks like unRAID never detects that it
That is done by the emhttp process which calls this script.
Sounds like something else is spinning the drives up.
I have a wrapper around the commands whilst in rc and was working on SAS spinup/down and fixes to smartctl.
Below is part of my go file and attached are the two wrappers.
hdparm and smartctl are moved and wrappers replace them and call the real command. You need to check it points to the correct real command in the wrapper.