[Pacemaker] migration only between nodes with identical hardware

James Harper james.harper at bendigoit.com.au
Mon Oct 1 03:49:10 EDT 2012

> On 2012-09-28 16:24, James Harper wrote:
> > I have two nodes running identical hardware which run Xen VM's, and want
> to add a third node to the cluster which can access the same clvm and iscsi
> resources, but it will not be identical hardware. The non-identical hardware
> means that to move a VM to this third node it it must be stopped then
> started, a migration will not work.
> >
> > This situation may not really come up as in most cases I'll use location
> resources to restrict VM's to only the first two nodes (third node will mostly
> be for a different purpose), but just in case I want to do that for one or two
> VMs, is it possible to come up with some sort of rule like:
> >
> > A->B = migration allowed
> > B->A = migration allowed
> > A->C = no migration allowed
> > B->C = no migration allowed
> create an asymmetrical cluster.

My cluster is already asymmetric

> add a node property, e.g.
>  > node xxx attributes service="web"
> create corresponding location rules, e.g.
> > location loc-web-fs-www web-fs-www \
> >         rule $id="loc-web-webfs-www-rule" 100: service eq web

A location rule like that will stop the service running on that node altogether won't it? That's not what I want. The services can run on nodes with non-identical hardware, they just can't live-migrate there, they have to be stopped on the old node then started on the new node.

A live migration under Xen allows the VM to see no loss of uptime and only a very small pause while the final part of the migration happens, but only if the CPU is the same (eg same brand (AMD/Intel) and same features)



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