From: Wakko Warner <wakko@animx.eu.org>
To: linux-kernel@vger.kernel.org
Subject: Re: Slow write performance with mpt2sas
Date: Tue, 11 Oct 2011 22:59:18 -0400 [thread overview]
Message-ID: <20111012025918.GA16695@animx.eu.org> (raw)
In-Reply-To: <20111012002556.GA32495@animx.eu.org>
Wakko Warner wrote:
> I've noticed that my SAS9212-4i4e is having write issues. I have a raid5 of
> 4 2tb seagate green drives and a raid5 of 3 300gb seagate 15k sas drives.
> Write performance on the green drives is fairly poor. The riad4 of 4 disks
> has a write performance of about 6-10mb/sec. My onboard sas controller
> (1068e chip IT mode) does not have this issue (I'm using raid6 on 8 of the
> same model green drives).
>
> Write performance on the 15k drives in raid 5 was 140mb/sec (4gb volume).
Sorry, this appears to be a KVM issue. I had forgotten that I was using
this under KVM. Adding cache=writeback fixed my problems (Also note, my
load before this went to >35 when writing, now it's no higher than about 9)
prev parent reply other threads:[~2011-10-12 2:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-12 0:25 Wakko Warner
2011-10-12 2:59 ` Wakko Warner [this message]
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