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From: Vladimir Bashkirtsev <vladimir@bashkirtsev.com>
To: Mark Nelson <mark.nelson@inktank.com>
Cc: Calvin Morrow <calvin.morrow@gmail.com>,
	Tommi Virtanen <tv@inktank.com>,
	Josh Durgin <josh.durgin@inktank.com>,
	ceph-devel@vger.kernel.org
Subject: Re: Poor read performance in KVM
Date: Fri, 20 Jul 2012 14:54:30 +0930	[thread overview]
Message-ID: <5008EB8E.30708@bashkirtsev.com> (raw)
In-Reply-To: <50084EC3.60003@inktank.com>


>
> We are seeing degradation at 64k node/leaf sizes as well.  So far the 
> degradation is most obvious with small writes.  it affects XFS as 
> well, though not as severely.  We are vigorously looking into it. :)
>
Just confirming that one of our clients has run fair amount (on 
gigabytes scale) of mysql updates in preceding few days. So it appears 
all performance degradation stems from random writes. Perhaps I will 
rebuild each osd to check if it would help to recover.

  reply	other threads:[~2012-07-20  5:24 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-15 13:13 Poor read performance in KVM Vladimir Bashkirtsev
2012-07-16  6:16 ` Josh Durgin
2012-07-18  5:46   ` Vladimir Bashkirtsev
2012-07-18 15:27     ` Josh Durgin
2012-07-19 10:46       ` Vladimir Bashkirtsev
2012-07-19 12:19       ` Vladimir Bashkirtsev
2012-07-19 15:52         ` Tommi Virtanen
2012-07-19 18:06           ` Calvin Morrow
2012-07-19 18:15             ` Mark Nelson
2012-07-20  5:24               ` Vladimir Bashkirtsev [this message]
2012-07-20  5:24             ` Vladimir Bashkirtsev
2012-07-20  5:20           ` Vladimir Bashkirtsev
     [not found]       ` <50080D9D.8010306@bashkirtsev.com>
2012-07-19 18:42         ` Josh Durgin
2012-07-20  5:31           ` Vladimir Bashkirtsev
2012-07-20 16:17           ` Vladimir Bashkirtsev
2012-07-20 16:42             ` Tommi Virtanen
2012-07-20 16:53               ` Mark Nelson
2012-07-20 16:53               ` Vladimir Bashkirtsev
2012-07-29 15:31               ` Vladimir Bashkirtsev
2012-07-29 16:13                 ` Mark Nelson
2012-07-18 15:34     ` Josh Durgin
2012-07-18  5:49   ` Vladimir Bashkirtsev
2012-07-18  5:51   ` Vladimir Bashkirtsev

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