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From: Stefan Priebe <s.priebe@profihost.ag>
To: Josh Durgin <josh.durgin@inktank.com>
Cc: "ceph-devel@vger.kernel.org" <ceph-devel@vger.kernel.org>
Subject: Re: optmize librbd for iops
Date: Tue, 13 Nov 2012 08:55:03 +0100	[thread overview]
Message-ID: <50A1FCD7.7090303@profihost.ag> (raw)
In-Reply-To: <50A1FC14.3010007@inktank.com>

Am 13.11.2012 08:51, schrieb Josh Durgin:
> On 11/12/2012 05:50 AM, Stefan Priebe - Profihost AG wrote:
>> Hello list,
>>
>> are there any plans to optimize librbd for iops? Right now i'm able to
>> get 50.000 iop/s via iscsi and 100.000 iop/s using multipathing with
>> iscsi.
>>
>> With librbd i'm stuck to around 18.000iops. As this scales with more
>> hosts but not with more disks in a vm. It must be limited by rbd
>> implementation in kvm / librbd.
>
> It'd be interesting to see which layers are most limiting in this
> case - qemu/kvm, librados, or librbd.
>
> How does rados bench with 4k writes and then 4k reads with many
> concurrent IOs do?
Right now i'm using qemu-kvm with librbd and fio inside guest. How does 
the rados bench work?

Stefan

  reply	other threads:[~2012-11-13  7:55 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-12 13:50 optmize librbd for iops Stefan Priebe - Profihost AG
2012-11-13  7:51 ` Josh Durgin
2012-11-13  7:55   ` Stefan Priebe [this message]
2012-11-13  8:20     ` Josh Durgin
2012-11-13 10:10       ` Stefan Priebe - Profihost AG

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