Spin Down HDDs

My HDDs on my Gentoo server don't ever seem to spin down. Is there a way I could fix this?

I'm running software RAID-5 using mdadm, if that matters (it shouldn't).

Add something like this to /etc/conf.d/hdparm:
Consult the hdparm man page for how to figure out the number for a given spindown interval - it's not straightforward.

The md raid driver works correctly with sleeping disks, if you and your applications can tolerate a few seconds of wakeup time.

I can tolerate it more than I can tolerate a dead drive.

Edit:Hmm, it looks as though the man page for hdparm disagrees with you on the value you said to pass:

Values from 1 to 240 specify multiples of 5 seconds, yielding timeouts from 5 seconds to 20 minutes. Values from 241 to 251 specify from 1 to 11 units of 30 minutes, yielding timeouts from 30 minutes to 5.5 hours.

Click to expand...

According to this, 242 would be one hour? Which is actually what I'd rather use anyway.

Anyway, I wasn't aware of how hdparm passed values on startup, so thank you for pointing me in the right direction.

You're right, 242 would be one hour. I posted it from memory, I thought I did well Don't forget to add the hdparm init script to your default runlevel, and each hard drive in the RAID array will need its own entry in /etc/conf.d/hdparm.