Hi all,Yuck, how stupid!
The subject may be a bit misleading since I haven't investigated the whole issue under other OS-es (nor do I plan to), but this is how the story goes..
Those fancy new WD GreenPower drives seem to be heavily suffering from the rapidly increasing head load/unload problem. And the bad thing is they don't respond to 'hdparm -B', which would mean (I think) their power management behaviour is solely up to their firmware.
I got one of them (WD5000AACS) recently and to my horror after less than three days of being power on this is what I saw:
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 66
193 Load_Cycle_Count 0x0032 197 197 000 Old_age Always - 10233
At this rate the disk would reach it's design limit for load/unload cycles in around 80 days. Not good - so I implemented a lame workaround of keeping disk busy every couple of seconds - hopefully that won't kill it sooner that unloads would..