Messages in this thread | | | Date | Tue, 24 Jun 2008 10:54:41 +0200 | From | Stefan Richter <> | Subject | Re: USB attached SATA disk idle spindown |
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(adding Cc: linux-usb and Johannes Niess)
On 6/24/2008 6:59 AM, Jonathan Steinert wrote at LKML: > Dear list, > > I am looking for what the current state of USB SATA timed spindown of- > disks is ata this time. I've been reading documents and mailing lists- > for every possible search I can dream up on the subject. Suggested- > workable solutions include (but are probably not limited to): > > $ hdparm -S > This seems to be the ATA way of telling a disk to spin down, and it > works in some situations, but doesn't appear to work on USB attached > disks under 2.6.25 > > $ sdparm > This is suggested in a small number of locations. Most of which have > examples on how to disable STANDBY on a handful of devices. I am > unable to find any evidence that it can actually be used to enable > power saving.
I think either of these depend on specific support by the USB to SATA bridge firmware.
I hear some newer bridges and their firmwares implement ATA pass-through. Would that help?
> $ scsi_spin > Requires the disk to be unmounted, and I can't find anything saying > that this is how the world is supposed to be.-
Johannes recently informed me that he wrote a script which is used like a background daemon to stop idle USB disks. The script uses - "cat /sys/block/${device}/stat" to watch disk activity, - "sdparm -q -C stop /dev/${device}" to stop the motor after longer inactivity.
> I'm hoping that perhaps I'm missing something from this list. > > I don't really know whether this is a topic for the scsi people, or the- > SATA people, or the USB people. So I'm asking here instead to try and > get my first hints from the parent group. > > Thanks in advance, > > hachi
IMO it is firstly an USB topic because it depends on the features and behaviour of the bridge and its firmware.
(PS: Don't have too high expectations of $15 devices.) -- Stefan Richter -=====-==--- -==- ==--- http://arcgraph.de/sr/
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