Re: How do put an ATA disk into sleep/standby mode?

On 2003.09.13 01:16:16 -0700, John-Mark Gurney <gurney_j_at_efn.org> wrote:

> Darren Pilgrim wrote this message on Thu, Sep 11, 2003 at 17:55 -0700:
> > In my workstation, running 5.1-R, I have two disks, one containing
> > FreeBSD, the other Windows.  Since the Windows disk isn't used at
> > all when in FreeBSD, I would like to put it into standby or sleep
> > mode(whichever is necessary) to make it spin down, reducing heat and
> > noise production--both of which have become a real problem.
> > 
> > This is at least technically possible, since spinning down a disk is
> > part of the APM sleep mode.  The capabilities list atacontrol
> > reports for the disk in question shows power management and advanced
> > power management as being supported, and I've gotten Windows to spin
> > down this disk.  I haven't had any luck figuring out how to do this
> > in FreeBSD, though.
> > 
> > So how do I accomplish this?
> 
> Well, in -current, sos has commited a frame work that will let a
> userland utility to send arbitrary commands to the disks, and so
> this will be possible from a utility.

I may just wait for 5.2 to work on this, then.

> I wanted this feature too, and I happen to be browsing around the ata
> spec and noticed that you can include a spin down time as part of the
> disk idle command..  The disk idle command appears to be quite
> harmless as it just asks the drive to go to idle (if it was doing a
> read ahead or something else).  So, I have this patch.  I originally
> did this against 4.2-R I believe, but I think I have updated it to a
> more recent version.. (the revisions it's against are in the patch)..
> 
> hope this helps you.

It does, in that it confirms that it's at least possible to spin down
disks without suspending the entire machine.

What I was thinking of, though, was a program or extension to atacontrol
that would send the standby or sleep signal and detach the device to
avoid having an unresponsive device entry.