Re: [Xen-API] [Project Kronos] SR_BACKEND_FAILURE_53 when creating SR

[Errol Neal <eneal@xxxxxxxxxxxxxxxxx>]

On Tue, 08/23/2011 04:02 PM, SÃbastien Riccio <sr@xxxxxxxxxxxxxxx> wrote:
> We use XAPI as the "Cluster lock manager"
> essentially. There is a strict notion of ordering of events, and XAPI
> always ensures that there is a single SRMaster for any shared SR. The SR
> master is the only entity that modifies LVM metadata, and it
> strategically refreshes slaves as necessary. Typically slaves only
> operate in an LVM Read-only mode, so the LVM metadata is refreshed when
> a slave needs to access a new logical volume, and the slave is only
> allowed to create device-mapper nodes, never to modify the LVM metadata.
> 
> There are patches to LVM to add an explicit 'master' flag, this ensures
> that non-masters never attempt to repair LVM metadata if ever it is read
> and found to be inconsistent. In practice this would never happen due to
> the way LVM updates its metadata and the fact that we do not allow
> shared Volume Groups that span more than one LUN, however it's an
> important safety catch.
> --

Are the patches available for use now?

_______________________________________________
xen-api mailing list
xen-api@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/mailman/listinfo/xen-api