On 07/09/2012 04:45 PM, Darrick J. Wong wrote: > > I suspect that /sys/devices/<bunch of sas topology here>/manage_start_stop = 0 > for the SATA devices hanging off the SAS controller. Yep, looks like you're right. For my system: # cat /sys/block/sd?/device/scsi_disk/*/manage_start_stop 1 1 1 1 1 0 0 0 0 0 0 0 0 Those first 5 disks are SATA disks on SATA controllers. The last 8 disks are SATA disks on the SAS controller. > Setting that sysfs > attribute to 1 is supposed to enable the SCSI layer to send TUR when it sees > "LU not ready", as well as spin down the drives at suspend/poweroff time. Setting it to 1 doesn't seem to have made any difference, however. # cat /sys/block/sdm/device/scsi_disk/14\:0\:7\:0/manage_start_stop 0 # echo 1 > /sys/block/sdm/device/scsi_disk/14\:0\:7\:/manage_start_stop # cat /sys/block/sdm/device/scsi_disk/14\:0\:7\:0/manage_start_stop 1 # hdparm -y /dev/sdm /dev/sdm: issuing standby command # hdparm -C /dev/sdm /dev/sdm: drive state is: standby # dd if=/dev/sdm of=/dev/null bs=512 count=1 dd: reading `/dev/sdm': Input/output error 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.00117802 s, 0.0 kB/s ... and on the scsi logging side, I see the read(10) to the disk which immediately returns "Not Ready" and the I/O failure bubbles up the chain. And afterwards, the disk is still asleep. # hdparm -C /dev/sdm /dev/sdm: drive state is: standby Also, TURs don't appear to actually wake the disk up (should they?). The only thing I've found that'll wake the disk up is an explicit START UNIT command. -- Rob -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
