Re: smartctl kills performance

Hello!
Can't reply directly into the thread like with Google Groups, but
anyway. I'm writing in reply to
http://sourceforge.net/p/smartmontools/mailman/message/29431706/ about
offline test kills the performace.

On the new server on Hetzner, strange performance degradation was
detected. During several days, degrade started at 4:15 AM, reboot
helped.

The server is equipped with disks:
root@phi1:~# for i in  /dev/sd?;do smartctl -i $i;done|grep Model
Device Model:     HGST HUS726060ALE610
Device Model:     HGST HUS726060ALE610
Device Model:     HGST HUS726060ALE610
Device Model:     HGST HUS726060ALE610

As revealed, when regular offline scan fires up (at 4:15 AM), disk
performance is slow as turtle.

Feb  6 04:15:01 phi1 smartd[2232]: Device: /dev/sdb [SAT], starting
scheduled Long Self-Test.
Feb  6 04:15:01 phi1 smartd[2232]: Device: /dev/sdc [SAT], starting
scheduled Long Self-Test.

I can see large awaits in iostat, collectd showed disk io time up to
75 seconds! ( http://gyazo.coolcold.org/upload/fe129abcc401bd61496273c32d4c.png
)

Stopping offline test with "-x" restores the performance.

May be this going to be useful to someone else.


P.S. I'm off the list, so if you want to reply, add me to CC/TO fields.
-- 
Best regards,
[COOLCOLD-RIPN]

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