From: Emmanuel Florac <eflorac@intellique.com>
To: quanjun hu <huquanjun@gmail.com>
Cc: xfs@oss.sgi.com
Subject: Re: Problem about very high Average Read/Write Request Time
Date: Sat, 18 Oct 2014 14:38:48 +0200 [thread overview]
Message-ID: <20141018143848.3baf3266@galadriel.home> (raw)
In-Reply-To: <CALSoAzD4ccHXBuD6mT3ggqMf1j_kDEK-RNMOeRLq+N+NiWVQXg@mail.gmail.com>
Le Sat, 18 Oct 2014 17:26:40 +0800 vous écriviez:
> Hi,
> I am using xfs on a raid 5 (~100TB) and put log on external ssd
> device, the mount information is:
> /dev/sdc on /data/fhgfs/fhgfs_storage type xfs
> (rw,relatime,attr2,delaylog,logdev=/dev/sdb1,sunit=512,swidth=15872,noquota).
> when doing only reading / only writing , the speed is very
> fast(~1.5G), but when do both the speed is very slow (100M), and high
> r_await(160) and w_await(200000).
What are your kernel version, mount options and xfs_info output ?
> 1. how can I reduce average request time?
> 2. can I use ssd as write/read cache for xfs?
Sure, using bcache and other similar tools.
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next prev parent reply other threads:[~2014-10-18 12:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-18 9:26 Problem about very high Average Read/Write Request Time quanjun hu
2014-10-18 12:38 ` Emmanuel Florac [this message]
2014-10-19 10:10 ` Peter Grandi
2014-10-20 8:00 ` Bernd Schubert
2014-10-21 18:27 ` Peter Grandi
2014-10-23 16:20 ` Bernd Schubert
2014-10-23 20:09 ` Peter Grandi
2014-10-24 21:45 ` Dave Chinner
2014-10-25 11:00 ` Peter Grandi
2014-10-25 19:31 ` Stan Hoeppner
2014-10-25 12:36 ` Peter Grandi
2014-10-23 23:01 ` Peter Grandi
2014-10-19 21:16 ` Stan Hoeppner
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