Re: Patch: allow devices to restrict start on add

[Douglas Gilbert <dougg@torque.net>]

Luben Tuikov wrote:
> Eddie Williams wrote:
> 
>>
>> Sense_Key=2 Not Ready
>> ASC: 0x04, ASQ: 0x02 Logical Unit Not Ready, Initializing Command 
>> Required
> 
> 
> Thanks Eddie.
> 
> Has anyone seen this condition for locally attached (same host)
> (block) devices?  Or is it only generated by the multipathing 
> soft/hardware.

Luben,
That ASC/ASQ sequence is precisely what I see after
I spin down a Fujitsu MAM3184 (ditto for a Seagate
ST318451). The disk below is directly attached with a
single initiator. The 'sg_start 0 /dev/sg3' command spins
down the second Fujitsu disk:

# lsscsi -g
[0:0:1:0]    disk    FUJITSU  MAM3184MP        0106  /dev/sda  /dev/sg0
[1:0:3:0]    disk    FUJITSU  MAM3184MP        0105  /dev/sdb  /dev/sg3
[2:0:0:0]    cd      ATAPI    CD-RW 48X16      A.RZ  -         /dev/sg1
[3:0:0:0]    cd      CREATIVE CD5233E          1.00  -         /dev/sg2
#
# sg_dd if=/dev/sg3 of=. bs=512 count=1
1+0 records in
1+0 records out
#
# sg_start 0 /dev/sg3
#
# sg_dd if=/dev/sg3 of=. bs=512 count=1
reading: scsi status: Check Condition
Current, Sense key: Not Ready
[valid=0] Info fld=0x0, Additional sense: Logical unit not ready, 
initializing cmd. required
Raw sense data (in hex):
   70 00 02 00 00 00 00 28 00 00 00 00 04 02 00 00 00 00 03 28 00 01 05 03
   00 00 00 00 00 00 00 00
plus...: Driver_status=0x08 (DRIVER_SENSE,SUGGEST_OK)
sg_read failed, skip=0
Some error occurred,  remaining block count=1
0+0 records in
0+0 records out

So ASC,ASQ=0x4,0x2 is the normal response for recent disks
when they are sent commands (typically other than INQUIRY)
when they are spun down.

> What I'd like to know is if this condition plus another (which I'm about
> to investigate) will give a pretty consistent rule for multipathed
> devices.

Doug Gilbert