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From: Paolo Bonzini <pbonzini@redhat.com>
To: Wolfgang Richter <wolf@cs.cmu.edu>
Cc: "Richard W.M. Jones" <rjones@redhat.com>,
	stefanha <stefanha@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [RFC] block-trace Low Level Command Supporting Disk Introspection
Date: Wed, 22 May 2013 18:11:50 +0200	[thread overview]
Message-ID: <519CEE46.5060605@redhat.com> (raw)
In-Reply-To: <CACO=3k6QwYKX6eA83zsP2RDeDwZRHD1PzpWKO8Qva6D1dRGkng@mail.gmail.com>

Il 22/05/2013 17:51, Wolfgang Richter ha scritto:
> On Thu, May 16, 2013 at 9:44 AM, Richard W.M. Jones <rjones@redhat.com
> <mailto:rjones@redhat.com>> wrote:
> 
>     Ideally I'd like to issue some QMP commands which would set up the
>     point-in-time snapshot, and then connect to this snapshot over (eg)
>     NBD, then when I'm done, send some more QMP commands to tear down the 
> 
>     snapshot.
> 
> 
> This is actually interesting.  Does the QEMU nbd server support multiple
> readers?

Yes.

> Essentially, if you're RWMJ (not me), and you're keeping a full
> mirror, it's clear that the mirror write stream goes to an nbd server,
> but is it possible to attach a reader to that same nbd server and read
> things back (read-only)?

Yes, it can be done with both qemu-nbd and the QEMU nbd server commands.

Paolo

  reply	other threads:[~2013-05-22 16:12 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-13 21:21 [Qemu-devel] [RFC] block-trace Low Level Command Supporting Disk Introspection Wolfgang Richter
2013-05-14  8:40 ` Stefan Hajnoczi
2013-05-14 15:42   ` Wolfgang Richter
2013-05-14  8:50 ` Kevin Wolf
2013-05-14 10:04   ` Paolo Bonzini
2013-05-14 15:48     ` Wolfgang Richter
2013-05-14 16:45       ` Paolo Bonzini
2013-05-14 19:30         ` Wolfgang Richter
2013-05-15  7:59         ` Kevin Wolf
2013-05-15  8:25           ` Paolo Bonzini
2013-05-15  8:53             ` Kevin Wolf
2013-05-15  9:16               ` Paolo Bonzini
2013-05-15  9:46                 ` Kevin Wolf
2013-05-15 11:54                   ` Paolo Bonzini
2013-05-22 15:46                     ` Wolfgang Richter
2013-05-14 15:45   ` Wolfgang Richter
2013-05-16 13:44 ` Richard W.M. Jones
2013-05-22 15:51   ` Wolfgang Richter
2013-05-22 16:11     ` Paolo Bonzini [this message]
2013-05-22 16:29       ` Wolfgang Richter
2013-05-22 16:42     ` Richard W.M. Jones
2013-05-22 18:32       ` Wolfgang Richter
2013-05-22 19:26         ` Richard W.M. Jones
2013-05-22 19:38           ` Wolfgang Richter
2013-05-22 20:47             ` Richard W.M. Jones
2013-05-22 21:46               ` Paolo Bonzini
2013-05-23  7:50                 ` Stefan Hajnoczi

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