Douglas Gilbert wrote:
Mi wrote at linux1394-devel:
I have 3 external firewire Maxtor One Touch III drives, which appear
to go into a "sleep" state after between one and two hours, and cannot
be accessed after that.
...
I later found scsi-spin which is also able to wake up the drive:
scsi-spin -u /dev/sdd
...
Note that there is absolutely nothing in the logs when the drive goes
to sleep. Only errors when I try to access them:
kernel: Device sdd not ready.
kernel: end_request: I/O error, dev sdd, sector 0
...
I believe the sd driver should issue a START STOP UNIT
(start) command when confronted with a "... initializing
command required" error [sk,asc,ascq: 2,4,2]. It also
needs to tell the block layer to go away and amuse itself
while it polls the device until it is ready.
When I suggested this some time ago, the response was that
whatever app was responsible for stopping the device bore
the responsibility for spinning it up again (i.e. "not our
problem").
The power condition state machine of ATA and SCSI differ
see: http://www.torque.net/sg/power.html
For devices that use SAT as a guide (and Maxtor seems to be)
the reported problem is going to become more signficant:
a) external device decides to spin itself down after
a period of inactivity
b) user later accesses mounted file system and sd driver
receives a "2,4,2" error
Thanks a lot for the pointer. This may indeed become more relevant now,
including SBP-2 enclosures because vendors have mixed IEEE 1394 and
(e)SATA product families now.
Mi, I would be glad to help and implement what Douglas described.
However there is still so much on my sbp2 todo-list that I'm not yet
considering to go hack other drivers.
--
Stefan Richter
-=====-=-==- --== ===-=
http://arcgraph.de/sr/
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