[mythtv-users] raid array spin down possible?

Neil Cooper neilcoo at yahoo.co.uk
Mon Sep 26 18:31:54 UTC 2011


My backend has a single 1TB HDD (for booting/OS and recorded TV shows) and also 3 HDDs in a raid array for saved shows, other media and general NAS. The array is a Linux "software" type (i.e. mdadm --create) raid 5. All drives are SATA. It's running "standard" Ubuntu 64 11.04 (not mythbuntu).

Both because the raid array is hardly ever in use and because the box gets very hot with all drives running, I would like to spin down (just) the raid array whenever possible.  

I've tried from the command line:
sudo hdparm -S 1 /dev/sdb /dev/sdc /dev/sdd 
I also have uncommented/modified the spindown setting to 1 in hdparm.conf but still the drives don't ever actually spin down. Even though nothing I'm doing is accessing the raid array.

The 1 value equals a spindown in 5 seconds of no-use. I'm reasonably (but not 100%) certain that the OS isn't accessing the array, at least not as often as every 5 seconds.

I read an earlier thread here that SATA drives might not respond to hdparm -S and that in those cases sg3-utils and/or spindown might work, however a later post disputed that. Also those seem to do the equivalent of ejecting the drive. I'm afraid to try them as I'm not even sure it would be safe with drives already in a raid array.

Any advice on how can I get my raid array to spin down?

Also, is there any way from the command line to see if a drive is actually in a spun down state or not?

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