Re: Does Linux support powering down SATA drives?

[James Courtier-Dutton <James@superbug.co.uk>]

Marc Perkel wrote:
> Trying to save power consumption. I have a backup drive that is used 
> only once a day to back up the main drive. So - why should I run it more 
> that 10 minutes a day? What I'd like to do is keep it in an off state 
> and then at night power it on, mount it up, do the backup, unmount it, 
> and shut it down. Can I do that?
> 

Support is being added soon, I think the latest 2.6.15-rc1 supports 
passthru. I had to install an extra patch due to a bug where it used the 
same IDE device irrespective of one asking for /dev/sda or /dev/sdb
I think the fix will be in rc2.

hdparm -S60 works fine for me. It spins down, and therefore stay nices a 
cool.
hdparm -y should work, and is like an immeadiate -S
hdparm -Y is kind of dangerous at the moment. It powers down the drive, 
but will not come back unless the entire IDE bus goes through a reset. 
The feature to support that is called hotplug, but that is not 
implemented yet for SATA. So, basically, if you do hdparm -Y, you won't 
be able to wake it up again at the moment. At least hdparm -S60 is a 
start towards what you want.

James