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From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>
Subject: Re: [Qemu-devel] [PATCH 3/8] qed: add support for Copy-on-Read
Date: Wed, 27 Apr 2011 16:29:41 +0200	[thread overview]
Message-ID: <4DB82855.9020301@redhat.com> (raw)
In-Reply-To: <1303910855-28999-4-git-send-email-stefanha@linux.vnet.ibm.com>

On 04/27/2011 03:27 PM, Stefan Hajnoczi wrote:
> From: Anthony Liguori<aliguori@us.ibm.com>
>
> When creating an image using qemu-img, just pass '-o copy_on_read' and then
> whenever QED reads from a backing file, it will write the block to the QED
> file after the read completes ensuring that you only fetch from the backing
> device once.
>
> This is very useful for streaming images over a slow connection.

While having the default in the file is sane, it seems to me that it 
should be overridable at runtime, too.

Paolo

  reply	other threads:[~2011-04-27 14:30 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-27 13:27 [Qemu-devel] [RFC PATCH 0/8] QED image streaming Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 1/8] block: add bdrv_aio_stream Stefan Hajnoczi
2011-04-29 11:56   ` Kevin Wolf
2011-05-06 13:21     ` Stefan Hajnoczi
2011-05-06 13:36       ` Kevin Wolf
2011-05-06 15:47         ` Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 2/8] qmp: Add QMP support for stream commands Stefan Hajnoczi
2011-04-29 12:09   ` Kevin Wolf
2011-05-06 13:23     ` Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 3/8] qed: add support for Copy-on-Read Stefan Hajnoczi
2011-04-27 14:29   ` Paolo Bonzini [this message]
2011-04-29 12:14   ` Kevin Wolf
2011-05-06 13:24     ` Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 4/8] qed: intelligent streaming implementation Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 5/8] qed: detect zero writes and skip them when to an unalloc cluster Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 6/8] blockdev: Allow image files to auto-enable streaming Stefan Hajnoczi
2011-04-29 12:20   ` Kevin Wolf
2011-04-27 13:27 ` [Qemu-devel] [PATCH 7/8] qed: Add QED_CF_STREAM flag " Stefan Hajnoczi
2011-04-27 13:27 ` [Qemu-devel] [PATCH 8/8] qed: Add -o stream=on image creation option Stefan Hajnoczi
2011-04-27 13:41 ` [Qemu-devel] [RFC PATCH 0/8] QED image streaming Stefan Hajnoczi

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