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From: "Richard W.M. Jones" <rjones@redhat.com>
To: Wolfgang Richter <wolf@cs.cmu.edu>
Cc: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] drive-mirror sync points
Date: Mon, 13 May 2013 22:50:49 +0100	[thread overview]
Message-ID: <20130513215049.GA13384@redhat.com> (raw)
In-Reply-To: <20130513214655.GA9846@redhat.com>

On Mon, May 13, 2013 at 10:46:55PM +0100, Richard W.M. Jones wrote:
> On Mon, May 13, 2013 at 01:50:00PM -0400, Wolfgang Richter wrote:
> > Paolo/anyone who knows -
> > 
> > Are drive-mirror sync points (NBD flush commands) reflecting guest write
> > barriers?  Are guest write barriers respected by drive-mirror?  If so, that
> > would make drive-mirror much more palatable for disk introspection work (a
> > drop-in usable feature of QEMU!).
> 
> I'm also interested in this question.  Further extensions to this
> (*not* drive-mirror on its own AIUI) which stefanha is working on
> should allow libguestfs to perform point-in-time snapshots of images,
> which will mean that we can do complex and long-running inspection
> operations on live guests.

OK, I got my attributions wrong there.  I see that Dietmar Maurer
wrote the original version of the patch and Stefan modified that.
Anyway I'm very interested in point-in-time snapshots.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming blog: http://rwmj.wordpress.com
Fedora now supports 80 OCaml packages (the OPEN alternative to F#)

  reply	other threads:[~2013-05-13 21:51 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-13 17:50 [Qemu-devel] drive-mirror sync points Wolfgang Richter
2013-05-13 19:05 ` Paolo Bonzini
2013-05-13 21:46 ` Richard W.M. Jones
2013-05-13 21:50   ` Richard W.M. Jones [this message]
2013-05-13 22:09   ` Wolfgang Richter

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