See the following step-by-step guide (complete w/ screenshots )
[1] that I threw together on how to use Aeolus and Snap [2] to
migrate a running instance between two separate cloud providers
with no downtime (demonstrated is EC2 / rackspace but this will
work to/from RHEV-M or any other cloud provider supported by
aeolus/deltacloud [3])
-Mo
[1] http://mo.morsi.org/blog/node/347