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Re: [Qemu-block] [PATCH COLO v3 01/14] docs: block replication's descrip
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-block] [PATCH COLO v3 01/14] docs: block replication's description |
Date: |
Tue, 5 May 2015 16:23:56 +0100 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
* Stefan Hajnoczi (address@hidden) wrote:
> On Fri, Apr 24, 2015 at 11:36:35AM +0200, Paolo Bonzini wrote:
> >
> >
> > On 24/04/2015 11:38, Wen Congyang wrote:
> > >> >
> > >> > That can be done with drive-mirror. But I think it's too early for
> > >> > that.
> > > Do you mean use drive-mirror instead of quorum?
> >
> > Only before starting up a new secondary. Basically you do a migration
> > with non-shared storage, and then start the secondary in colo mode.
> >
> > But it's only for the failover case. Quorum (or a new block/colo.c
> > driver or filter) is fine for normal colo operation.
>
> Perhaps this patch series should mirror the Secondary's disk to a Backup
> Secondary so that the system can be protected very quickly after
> failover.
>
> I think anyone serious about fault tolerance would deploy a Backup
> Secondary, otherwise the system cannot survive two failures unless a
> human administrator is lucky/fast enough to set up a new Secondary.
I'd assumed that a higher level management layer would do the allocation
of a new secondary after the first failover, so no human need be involved.
Dave
> Stefan
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- Re: [Qemu-block] [PATCH COLO v3 01/14] docs: block replication's description,
Dr. David Alan Gilbert <=