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.
$ 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.-
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
------------------------------------------------------------------------
"She smiled again, shrugged her shoulders, and became a perfect mirror."
------------------------------------------------------------------------
(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 $15 devices.)
--
Stefan Richter
-=====-==--- -==- ==---
http://arcgraph.de/sr/
Stefan Richter wrote:
> Johannes recently informed me that he wrote a script which is used like
> a background daemon to stop idle USB disks. The script uses
> - "cat /sys/block/${device}/stat" to watch disk activity,
> - "sdparm -q -C stop /dev/${device}" to stop the motor after
> longer inactivity.
PS: I have seen START STOP UNIT with START=0 to be dangerous with some
FireWire firmwares. (Motor cannot be restarted after that anymore.)
Other firmwares ignore the START bit and look only at the POWER
CONDITIONS field. I expect various similar firmware quirks in USB land.
--
Stefan Richter
-=====-==--- -==- ==---
http://arcgraph.de/sr/
Stefan Richter wrote:
> (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?
Yeah, ATA pass through is all that's needed for hdparm -S to work.
--
tejun