Who wakes up the hard drive?

[shturm]

How to find out which application wakes up a hard drive?

"hdparm -C /dev/hdb" shows that it's "standby".
Then, after some time, I check it again, and now it's "active/idle".

[shturm]

I unmounted this drive, and this behavior still reproduces.
So it must be some process that works with devices directly that wakes up the hard drive.

Any ideas?

Your help will be greatly appreciated!

[zraffz]

I need to know also.