openstack team mailing list archive

[Eric Day <eday@xxxxxxxxxxxx>]

On Wed, Mar 23, 2011 at 07:40:20PM +0000, Ed Leafe wrote:
> > Migrations outside of a zone would require a new
> > instance ID, but this should be fine, since other things would also
> > change (such as IP, available volumes, ...). 
> 
> 	That's probably true in the Rackspace use case, as zones would most likely be physically separate hardware, but nothing about zones makes that mandatory. 

It does currently, I wasn't speaking specifically to Rackspace's
use case. Right now some network and volume code are not aware of
cross-zone issues, and instead assume they are the authority for things
like configured IP ranges. We can certainly change this, and if we
do want to allow proper instance migrations between zones, we would
need to allow instance IDs to change. I don't see the importance of
enabling cross-zone migrations (backup+restore seems sufficient). I
may be wrong, but if we did enable this functionality in the future,
I don't see a reason not to allow resource IDs to change.

Sounds like a design summit topic if folks feel we should support this.

-Eric