From: Carla Mott <carla.mott_at_oracle.com>
Date: Mon, 04 Oct 2010 11:59:57 -0700

If I try to stop an instance that is already stopped is that a success
or failure. stop-instance and stop-local-instance diff on this. I
think it is a failure if you try to stop an instance if it is already
stopped but wanted to verify.

Thanks,
Carla