[Libvir] Re: Next features and target for development
Dan Smith wrote:
RJ> Some issues around migration which are up for discussion:
Something else to consider is whether or not we "undefine" hosts
leaving one machine during a migration. Last time I checked, Xen left
a domain in "powered-off" state on the source. It seems to make more
sense to me for a migration to remove the shell domain from the source
machine.
What will be the expected behavior here?
For KVM, the guest isn't destroyed explicitly after a migration is
successful. Instead, the source guest is left in a paused state. The
main reason for not destroying the guest was so that a management tool
could still interact with the guest's monitor to obtain statistics on
the migration. It's expected that the management tool will destroy the
domain on the source machine whenever it is done working with it.
The KVM source guest is still resumable too so this doubles as a
mechanism for forking VMs. I think these are useful semantics that
ought to be exposed. With KVM, live migration is more generic. You can
use it to do light-weight checkpointing.
Regards,
Anthony Liguori