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Date: Thu, 10 Mar 2011 09:58:02 +0000
Message-ID: <AANLkTinkrhi0si34BRdhtx93uGiXMwyRMCW6q9vHDc6p@mail.gmail.com>
Subject: Re: [Qemu-devel] Issue with snapshot outside qcow2 disk - qemu 0.14.0
From: Stefan Hajnoczi <stefanha@gmail.com>
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To: Jes Sorensen <Jes.Sorensen@redhat.com>
Cc: SAURAV LAHIRI <saurav_lahiri@yahoo.com>, qemu-devel@nongnu.org

On Thu, Mar 10, 2011 at 9:32 AM, Jes Sorensen <Jes.Sorensen@redhat.com> wro=
te:
> On 03/10/11 10:27, Stefan Hajnoczi wrote:
>> I have CCed Jes who has been working on a live snapshot mechanism. =A0He
>> recently added the snapshot_blkdev monitor command that takes a
>> snapshot of a block device while the VM is running. =A0A new image file
>> is created based off the original image file (which will no longer be
>> modified), all new disk writes go to the new image file. =A0It is safe
>> to perform read-only access to the original image file. =A0There
>> currently is no support to merge the snapshot changes back into the
>> original image while the VM is running, but I think that is the next
>> planned step.
>
> Yes, keep in mind that the live snapshot is only for external snapshot
> files, it doesn't deal with internal snapshots.

Yep, that's why I'm interested in Saurav's use case.  Many use cases
work with either internal or external snapshot but it depends on the
details.

Stefan