From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stefan Hajnoczi <stefanha@gmail.com>
Subject: Re: [Qemu-devel] [RFC PATCH 1/1] ceph/rbd block driver for qemu-kvm
Date: Mon, 24 May 2010 09:27:29 +0100
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Cc: Anthony Liguori <anthony@codemonkey.ws>,
	Christian Brunner <chb@muc.de>,
	Blue Swirl <blauwirbel@gmail.com>, kvm@vger.kernel.org,
	qemu-devel@nongnu.org, ceph-devel@vger.kernel.org
To: Avi Kivity <avi@redhat.com>
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On Sun, May 23, 2010 at 1:01 PM, Avi Kivity <avi@redhat.com> wrote:
> On 05/21/2010 12:29 AM, Anthony Liguori wrote:
>>
>> I'd be more interested in enabling people to build these types of storage
>> systems without touching qemu.
>>
>> Both sheepdog and ceph ultimately transmit I/O over a socket to a central
>> daemon, right?
>
> That incurs an extra copy.

Besides a shared memory approach, I wonder if the splice() family of
syscalls could be used to send/receive data through a storage daemon
without the daemon looking at or copying the data?

Stefan