On 11/10/13 09:00, Mark Rogers wrote:
On 10 October 2013 22:27, steve-ALUG@hst.me.uk wrote:
Out of interest, I wonder if
hdparm -I /dev/sda
shows anything interesting, adjusting to your drive names as appropriate.
Define "interesting"!
Well I thought it was interesting :-)
So, it seems that some WD Green drives have had problems, that seem to be solved (at least once) by disabling NCQ - Native Command Queuing.
OK, sounds like it wouldn't do me any harm to disable it (hdparm confirms it's enabled). However the two steps of performing a zero-fill, then setting the idle time to 300s, prior to rebuilding the array has resulted in a fully functioning array this morning. My instinct is that it was the idle timeout change that fixed it, particularly in light of the thread you found.
Indeed. Yay it's working! :-))))
{}
It appears that NCQ can be disabled by
$ echo 1 > /sys/block/sda/device/queue_depth $ echo 1 > /sys/block/sdb/device/queue_depth
I note that hdparm -Q can report and set the queue depth (currently set to 31). Any suggestions from anyone as to which way I *should* disable NCQ?
The thread had this solution from Stephan Seitz at 29/07/2009 "No, not sysctl.conf, use /etc/sysfs.conf (package sysfsutils). You can then add the two lines: block/sda/device/queue_depth=1 block/sdb/device/queue_depth=1"
I'm sure any will work, but I "echo" won't survive a reboot. I don't know if setting hdparm will survive a reboot, or if you'll need to schedule it to run on startup. The above is supposed to work. Dunno though as I've not tried it.
Glad it's working. Long may it continue.
Steve