Thread (49 messages) 49 messages, 9 authors, 2007-10-11

Re: RAID 5 performance issue.

From: Justin Piszcz <hidden>
Date: 2007-10-05 13:18:57


On Fri, 5 Oct 2007, Andrew Clayton wrote:
On Fri, 5 Oct 2007 07:08:51 -0400 (EDT), Justin Piszcz wrote:
quoted
The mount options are from when the filesystem was made for
sunit/swidth I believe.

        -N     Causes the file system parameters  to  be  printed
out  without really creating the file system.

You should be able to run mkfs.xfs -N /dev/md0 to get that
information.
Can't do it while it's mounted. would xfs_info show the same stuff?
quoted
/dev/md3        /r1             xfs
noatime,nodiratime,logbufs=8,logbsize=262144 0 1

Try using the following options and the AS scheduler and let me know
if you still notice any 'hangs'
OK, I've remounted (mount -o remount) with those options.
I've set the strip_cache_size to 8192
I've set the nr_requests back to 128
I've set the schedulers to anticipatory.

Unfortunately problem remains.

I'll try the noop scheduler as I don't think I ever tried that one.
quoted
Justin.
Andrew
How are you measuring the problem?  How can it be reproduced?

Justin.
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