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Re: [Xen-devel] bad write performance with qdisk with larger files in pv

To: Ronny Hegewald <ronny.hegewald@xxxxxxxxx>
Subject: Re: [Xen-devel] bad write performance with qdisk with larger files in pv-domU
From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Date: Mon, 6 Jun 2011 12:49:29 +0100
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
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On Sat, 4 Jun 2011, Ronny Hegewald wrote:
> > > Is this performance-impact expected when no AIO is used?
> >
> > Yeah, it is slow.
> Ok, then no reason to dig deeper into that. So my current impression is that 
> its better not use qdisk/qemu-blktap until xen can use upstream qemu?

Yes, indeed.
Also bear in mind that blkback is a very good option for LVM or physical
partitions, but it is not very fast for raw files.

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