possible bus loading problem during resync
This was ment to goto the list. Keep forgetting, this list uses responder instead of list for reply address.
-------- Original Message --------
Subject: Re: possible bus loading problem during resync
Date: Wed, 10 Mar 2010 17:04:07 -0700
From: Timothy D. Lenz <[email protected]>
To: Asdo <[email protected]>
Quoted 32 lines · Asdo
Quoted 15 lines · Kristleifur Daðason
Quoted 4 lines · Timothy D. Lenz
I'm working on 2 systems that are mainly for running vdr. I've had these running somewhat for awhile with raid. But a couple nights ago as I was quitting for the night, I noticed one of the computers drive light staying
Quoted 8 lines
on. I had just made some changes to xine and didn't know if something had
crashed. Turned on the TV and found the video was freezing for 10-20secs every 10-20secs. Logging in using putty and winscp I found it very sluggish
to respond.Starting top I found it was doing the regular array check/resync.......
--Quoted 3 lines
Sorry about the incredibly brief answer: Not to dismiss other issues, but that behavior seems like exactly what I've seen when a disk has been failing.
If that is true, how does that happen, the driver is hung? But anyway, how can such things happen when there is more than one CPU-core?
try disabling NCQ by echo 1 >
/sys/block/sdX/device/queue_depthfor all drives. After doing this, at most 1 request can be issued to one drive until the drive has serviced such request.After doing this, firstly I'd say the sluggishness should disappear, at least on SSH when not touching the disks. And then you can look with "iostat -x 1": probably the bad drive will have a service time (svctm) or await much worse than the others.
Quoted 6 lines
Just guesses, correct me if I'm wrong
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First output is 5.12 for sda and 1.15 for sdb every time it's started. then mostly 0 for both. When there are numbers it changes back and forth between then as to which is greater.
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
sda 6.90 30.46 2.09 1.90 1164.19 258.92 356.52 0.10 23.99 5.12 2.04 sdb 0.16 30.46 8.84 1.90 1165.65 258.92 132.67 0.02 2.25 1.51 1.62
Was this test supposed to be done while it was doing a sync? Because it was the same if I made the change to 1 or put them back to the default value 31.
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