Re: [Qemu-devel] [PATCH V19 00/12] Quorum block filter

[Benoît Canet]

The Friday 21 Feb 2014 à 15:49:15 (-0700), Eric Blake wrote :
> On 02/21/2014 02:21 PM, Benoît Canet wrote:
> > Hi this is the latest version of the quorum block filter.
> > 
> > This version fix the qmp events and a small rebase conflict.
> > 
> > tested:
> > 
> > tested that json qmp string are correct and parse well with python
> > 
> > Ran qemu-iotest including 081 ok
> > 
> > quorum command line ok
> > quorum command line snapshot transaction ok
> > quorum QMP by reference ok
> > quorum QMP by reference and snapshot transaction ok
> > quorum QMP at once ok
> > quorum QMP at once and snapshot transaction ok
> 
> Generic question:
> 
> When the quorum detects mismatch but there was still a majority, is
> there a way to request that the quorum correct the odd man out?  That
> is, if I have a 2/3 quorum, and files A and B read '1' while C reads
> '2', can the mere act of reading that sector be used to write '1' into C?
> 
> Obviously, this should be an optional mode, not enabled by default; but
> I could envision creating a self-healing redundant array via this method.

That's part of the optional features I want to add.
I choose to start small to get it merged faster.

I also plan to modify drive-mirror to do a bdrv_swap when the mirroring is
finished in order to replace a faultly quorum file.

Best regards

Benoît

> 
> -- 
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>