Re: [Qemu-devel] [PATCH V19 06/12] quorum: Add quorum mechanism.

[Benoît Canet]

The Friday 21 Feb 2014 à 15:09:42 (-0700), Eric Blake wrote :
> On 02/21/2014 02:21 PM, Benoît Canet wrote:
> > From: Benoît Canet <address@hidden>
> > 
> > This patchset enables the core of the quorum mechanism.
> > The num_children reads are compared to get the majority version and if this
> > version exists more than threshold times the guest won't see the error at 
> > all.
> 
> > +++ b/docs/qmp/qmp-events.txt
> > @@ -500,3 +500,39 @@ Example:
> >  
> >  Note: If action is "reset", "shutdown", or "pause" the WATCHDOG event is
> >  followed respectively by the RESET, SHUTDOWN, or STOP events.
> > +
> > +QUORUM_FAILURE
> > +--------------
> 
> This should have been inserted in sorted order to match the rest of the
> file, rather than at the end.  Can be rearranged in a followup patch,
> now that this series is queued.
> 
> > +
> > +Emitted by the Quorum block driver if it fails to establish a quorum.
> > +
> > +Data:
> > +
> > +- "reference":    device name if defined else node name.
> > +- "sector-num":   Number of the first sector of the failed read operation.
> 
> I'm assuming sector-num is relative to the guest's view of the data?
Yes,

> 
> > +
> > +QUORUM_REPORT_BAD
> > +-----------------
> > +
> > +Emitted to report a corruption of a Quorum file.
> > +
> > +Data:
> > +
> > +- "ret":          The IO return code.
> 
> What values is this likely to contain?  Is it a finite set, in which
> case it would be nice to have a QAPI enum that describes the set of
> return codes, rather than a raw number?

It's anything that the block stack could return as an error.

> 
> I'd like to make sure we are happy with the wire format of this QMP
> event before it gets baked into 2.0.

Ok

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