From: Paolo Bonzini <pbonzini@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Kevin Wolf <kwolf@redhat.com>, Jeff Cody <jcody@redhat.com>,
mtosatti@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com,
Federico Simoncelli <fsimonce@redhat.com>,
Luiz Capitulino <lcapitulino@redhat.com>
Subject: Re: [Qemu-devel] drive transactions (was Re: [PATCH 2/2 v2] Add the blockdev-reopen and blockdev-migrate commands)
Date: Mon, 27 Feb 2012 17:51:47 +0100 [thread overview]
Message-ID: <4F4BB4A3.6080407@redhat.com> (raw)
In-Reply-To: <4F4BA044.5040208@codemonkey.ws>
On 02/27/2012 04:24 PM, Anthony Liguori wrote:
>
> Then you get an error with the block devices still frozen. You can
> execute another command to reopen back to the old image to roll back the
> transaction.
>
> Pushing the rollback logic to the client does make the client interface
> a bit more complicated and adds latency to the error path but it's much
> easier than building a complex transaction infrastructure.
>
> And there are examples of this in the wild too. LDAP uses a similar
> mechanism.
Actually, have you seen Jeff's atomic snapshot patch? It really
implements all that is needed to do transactions, and gets 100% ok
error-recovery unlike the existing blockdev_snapshot_sync. It really
looks like we can do better than client-side error management, and there
is not that much complexity at all.
Jeff could rework his patches to work with transaction begin/commit
commands, and Federico can then add drive-reopen and drive-migrate on top.
Paolo
next prev parent reply other threads:[~2012-02-27 16:52 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-22 17:13 [Qemu-devel] Live Block Migration using Mirroring Federico Simoncelli
2012-02-22 17:13 ` [Qemu-devel] [PATCH 1/3] Add blkmirror block driver Federico Simoncelli
2012-02-23 16:14 ` Stefan Hajnoczi
2012-02-23 16:18 ` Stefan Hajnoczi
2012-02-23 16:20 ` Federico Simoncelli
2012-02-23 16:28 ` Stefan Hajnoczi
2012-02-23 16:51 ` Federico Simoncelli
2012-02-23 16:18 ` Federico Simoncelli
2012-02-27 9:23 ` Stefan Hajnoczi
2012-02-27 11:37 ` Paolo Bonzini
2012-02-27 11:42 ` Stefan Hajnoczi
2012-02-27 11:48 ` Paolo Bonzini
2012-02-27 13:09 ` Stefan Hajnoczi
2012-02-27 13:47 ` Paolo Bonzini
2012-02-27 14:49 ` Stefan Hajnoczi
2012-02-27 14:59 ` Stefan Hajnoczi
2012-02-27 15:08 ` Paolo Bonzini
2012-02-22 17:13 ` [Qemu-devel] [PATCH 2/3] Update the " Federico Simoncelli
2012-02-23 7:18 ` Paolo Bonzini
2012-02-23 9:44 ` Federico Simoncelli
2012-02-23 9:45 ` Paolo Bonzini
2012-02-22 17:13 ` [Qemu-devel] [PATCH 3/3] Add nocreate option to snapshot_blkdev Federico Simoncelli
2012-02-23 7:19 ` Paolo Bonzini
2012-02-23 7:38 ` Paolo Bonzini
2012-02-23 9:39 ` Federico Simoncelli
2012-02-23 9:48 ` Paolo Bonzini
2012-02-23 10:19 ` Federico Simoncelli
2012-02-23 11:30 ` Paolo Bonzini
2012-02-23 15:47 ` [Qemu-devel] Live Block Migration using Mirroring Stefan Hajnoczi
2012-02-23 16:10 ` Federico Simoncelli
2012-02-23 16:35 ` Stefan Hajnoczi
2012-02-23 17:06 ` Federico Simoncelli
2012-02-24 11:37 ` [Qemu-devel] [PATCH 1/2] Add blkmirror block driver Federico Simoncelli
2012-02-24 11:37 ` [Qemu-devel] [PATCH 2/2] Add the blockdev-reopen and blockdev-migrate commands Federico Simoncelli
2012-02-24 12:03 ` Kevin Wolf
2012-02-24 12:12 ` Federico Simoncelli
2012-02-24 13:11 ` Paolo Bonzini
2012-02-24 17:04 ` Luiz Capitulino
2012-02-27 14:57 ` Markus Armbruster
2012-02-24 16:49 ` [Qemu-devel] [PATCH 1/2 v2] Add blkmirror block driver Federico Simoncelli
2012-02-24 17:02 ` Eric Blake
2012-02-24 17:15 ` Federico Simoncelli
2012-02-24 18:49 ` Paolo Bonzini
2012-02-24 18:17 ` Luiz Capitulino
2012-02-27 9:17 ` Federico Simoncelli
2012-02-24 16:49 ` [Qemu-devel] [PATCH 2/2 v2] Add the blockdev-reopen and blockdev-migrate commands Federico Simoncelli
2012-02-24 17:46 ` Eric Blake
2012-02-24 18:57 ` Paolo Bonzini
2012-02-24 19:37 ` Eric Blake
2012-02-24 19:01 ` Luiz Capitulino
2012-02-24 19:40 ` Eric Blake
2012-02-24 20:26 ` Luiz Capitulino
2012-02-24 22:46 ` Eric Blake
2012-02-24 20:32 ` Paolo Bonzini
2012-02-24 20:36 ` Luiz Capitulino
2012-02-24 21:05 ` Paolo Bonzini
2012-02-24 22:30 ` Eric Blake
2012-02-25 6:47 ` Paolo Bonzini
2012-02-27 11:29 ` Federico Simoncelli
2012-02-27 12:12 ` Luiz Capitulino
2012-02-27 12:49 ` Paolo Bonzini
2012-02-27 13:06 ` Luiz Capitulino
2012-02-27 14:39 ` [Qemu-devel] drive transactions (was Re: [PATCH 2/2 v2] Add the blockdev-reopen and blockdev-migrate commands) Paolo Bonzini
2012-02-27 14:46 ` Anthony Liguori
2012-02-27 14:54 ` Paolo Bonzini
2012-02-27 14:59 ` Anthony Liguori
2012-02-27 15:03 ` Paolo Bonzini
2012-02-27 15:06 ` Anthony Liguori
2012-02-27 15:17 ` Kevin Wolf
2012-02-27 15:24 ` Anthony Liguori
2012-02-27 16:51 ` Paolo Bonzini [this message]
2012-02-27 16:58 ` Anthony Liguori
2012-02-27 17:06 ` Paolo Bonzini
2012-02-27 16:33 ` Federico Simoncelli
2012-02-27 16:41 ` Paolo Bonzini
2012-02-27 16:42 ` Anthony Liguori
2012-02-27 16:50 ` Federico Simoncelli
2012-02-27 16:53 ` Anthony Liguori
2012-02-27 16:54 ` Paolo Bonzini
2012-02-27 16:59 ` Anthony Liguori
2012-02-27 17:37 ` Luiz Capitulino
2012-02-28 15:47 ` [Qemu-devel] Live Block Migration using Mirroring Stefan Hajnoczi
2012-02-28 17:15 ` Federico Simoncelli
2012-02-28 17:36 ` Paolo Bonzini
2012-02-28 17:46 ` Federico Simoncelli
2012-02-28 18:02 ` Paolo Bonzini
2012-02-28 18:21 ` Federico Simoncelli
2012-02-28 17:26 ` Paolo Bonzini
2012-02-29 12:28 ` [Qemu-devel] [PATCHv3] Add blkmirror block driver Federico Simoncelli
2012-02-29 13:02 ` Federico Simoncelli
2012-02-29 17:01 ` [Qemu-devel] [PATCHv4] " Federico Simoncelli
2012-03-05 16:59 ` [Qemu-devel] Live Block Migration using Mirroring Marcelo Tosatti
2012-03-05 17:20 ` Eric Blake
2012-03-05 17:44 ` Marcelo Tosatti
2012-03-05 18:05 ` Paolo Bonzini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F4BB4A3.6080407@redhat.com \
--to=pbonzini@redhat.com \
--cc=anthony@codemonkey.ws \
--cc=armbru@redhat.com \
--cc=fsimonce@redhat.com \
--cc=jcody@redhat.com \
--cc=kwolf@redhat.com \
--cc=lcapitulino@redhat.com \
--cc=mtosatti@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.