On 03/30/2018 03:07 PM, Tim Walker wrote:

Hi Doug-

Currently, the dual actuator firmware safely spins the drive down if
either LUN receives the START STOP UNIT command.  In other words, if
LUN1 receives the command, it will flush any dirty data from LUN1l and
LUN0, then spin down, taking both LUN1 & LUN0 off line. Alternatively,
we've had input that either:
a) Both LUNs must receive the START STOP UNIT command before the drive
will spin down, OR
b) Move the storage to LUN1 & LUN2, keeping LUN0 (with no storage) for
device specific commands such as START STOP UNIT that do not directly
access the media.

That will get interesting when suspending the device; physical
interactions between independent LUNs are always tricky. And I don't
even want to imagine the implications when assigning each LUN to
individual VM guests; shutting down one VM will also interfere with the
other VM ... shudder.

Actually I would propose to have a 'management' LUN at LUN0, who could
handle all the device-wide commands (eg things like START STOP UNIT,
firmware update, or even SMART commands), and ignoring them for the
remaining LUNs.

I guess that would make the whole setup easier to handle.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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