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From: Eric Blake <eblake@redhat.com>
To: Yaodong Yang <yaodong.yangy@gmail.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] vm live storage migration approach.
Date: Fri, 30 Jan 2015 12:21:44 -0700	[thread overview]
Message-ID: <54CBD9C8.2040909@redhat.com> (raw)
In-Reply-To: <CAJ3ZQbPzD_yBQay=xzMFPrtW-zMPFKA7Nd=sWG_J+cU+y-9gUA@mail.gmail.com>

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On 01/30/2015 09:25 AM, Yaodong Yang wrote:
> Hi all,
> 
> I'm investigating the current schemes for the VM live storage migration in
> QEMU system. I have the following questions:
> 
> 1. What is the functionality of drive_mirror in QEMU? Is it designed as a
> VM live storage migration approach?

Yes. drive-mirror was added precisely to support live storage migration.

> 
> 2. What's the difference between drive_mirror and vMotion? I learned that
> vMotion employs IO Mirroring mechanism to migration a running VM with all
> the virtual disk images. Are there any other mechanisms inside QEMU serve
> this purpose as well?

vMotion is not part of qemu, so I'm not sure what it does.  Therefore, I
cannot make a fair comparison.

> 
> I'm looking for a mechanism in QEMU, which is similar to vMotion ( IO
> Mirroring) in ESX environment.

Look at drive-mirror, block-backup, quorum drives, and lots of recent
threads on this list about adding redundant processing (such as the term
"COLO") for how to piece together lower-level blocks into whatever drive
mirroring scheme you can think of.


-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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  reply	other threads:[~2015-01-30 19:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-30 16:25 [Qemu-devel] vm live storage migration approach Yaodong Yang
2015-01-30 19:21 ` Eric Blake [this message]
2015-01-30 20:13   ` Yaodong Yang
2015-01-30 20:37     ` Stefan Hajnoczi
2015-01-30 20:39       ` Yaodong Yang

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