qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Lieven <pl@dlhnet.de>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [Qemu-devel] Block Migration and xbzrle
Date: Tue, 02 Oct 2012 12:09:44 +0200	[thread overview]
Message-ID: <506ABD68.4060508@redhat.com> (raw)
In-Reply-To: <135E8E0A-174B-4A0A-ABF3-9B41F224F88A@dlhnet.de>

Il 02/10/2012 11:44, Peter Lieven ha scritto:
> 
> Am 02.10.2012 um 11:38 schrieb Paolo Bonzini:
> 
>> Il 16/09/2012 12:39, Peter Lieven ha scritto:
>>>
>>> I remember that this was broken some time ago and currently with
>>> qemu-kvm 1.2.0 I am still not able to use
>>> block migration plus xbzrle. The migration fails if both are used
>>> together. XBZRLE without block migration works.
>>>
>>> Can someone please advise what is the current expected behaviour?
>>
>> Block migration is broken by design.  It will converge really slowly as
>> soon as you have real load in the VMs, and it will hamper the
>> convergence of RAM as well.
>>
>> Hopefully a real alternative will be in 1.3 (based on drive-mirror on
>> the source + an embedded NBD server running on the destination), then in
>> 1.4 we can reimplement the block migration monitor commands using the
>> alternative.
> 
> Hi Paolo, i know that block migration is not that good, but it seems that
> there is a bug in XBZRLE that is independent of block migration.

Understood---but hopefully you can stop using it with 1.3, which would
also work around the bug. :)

Paolo

      reply	other threads:[~2012-10-02 10:09 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-16 10:39 [Qemu-devel] Block Migration and xbzrle Peter Lieven
2012-09-17 18:03 ` Orit Wasserman
2012-10-02  8:33   ` lieven-lists
2012-10-02  9:28     ` Orit Wasserman
2012-10-02  9:30       ` Peter Lieven
2012-10-02 10:40         ` Orit Wasserman
2012-10-04  6:31           ` Peter Lieven
2012-10-02  9:38 ` Paolo Bonzini
2012-10-02  9:44   ` Peter Lieven
2012-10-02 10:09     ` Paolo Bonzini [this message]

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=506ABD68.4060508@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=pl@dlhnet.de \
    --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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).