From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55099) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XjR1A-0001Sj-JB for qemu-devel@nongnu.org; Wed, 29 Oct 2014 07:02:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XjR15-00071C-W3 for qemu-devel@nongnu.org; Wed, 29 Oct 2014 07:02:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58119) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XjR15-000717-Hd for qemu-devel@nongnu.org; Wed, 29 Oct 2014 07:02:15 -0400 Date: Wed, 29 Oct 2014 11:01:59 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20141029110158.GE2310@work-vm> References: <1411464235-5653-1-git-send-email-yanghy@cn.fujitsu.com> <54508EF5.8000908@cn.fujitsu.com> <20141029093457.GB2310@work-vm> <5450BF1F.4040801@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5450BF1F.4040801@cn.fujitsu.com> Subject: Re: [Qemu-devel] [RFC PATCH v2 00/23] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hongyang Yang Cc: Gui Jianfeng , Jiang Yunhong , Dong Eddie , qemu-devel@nongnu.org, "Michael R. Hines" , Paolo Bonzini , Walid Nouri * Hongyang Yang (yanghy@cn.fujitsu.com) wrote: > Hi Dave, > >For the COLO disk replication; are you talking here about 'local storage' > >and treating it as 'internal state' or 'external state' (as described in the > >first half of 4.4 in the original COLO paper)? > > 'local storage' and 'internal state'. This is what later half of 4.4 said: > 'COLO considers the state of local storage device as an internal s- > tate of the guest, and snapshots the local storage state as part of the > VM checkpoint, and plans to explore the other solution in future.' Thanks for the clarification. Dave > > > > >I know some groups would like to take advantage of facilities in the storage > >layer to help; e.g. take snapshots/rollback etc - so I think it's best > >to do (1) but make the interface clean so that other mechanisms could be added. > >Similarly I guess things like scsi-xcopy might help for some people - I'm > >not saying implement these, just if possible make an interface where it could > >fit later. > > > >It's probably best to check with the QEMU storage guys that you can reuse > >anything they have; there was a discussion a few weeks back where I cc'd > >Fam, Stefan and Kevin in). > > > >Dave > > > >-- > >Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > >. > > > > -- > Thanks, > Yang. -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK