Comment 0 for bug 1487151

Currently, if you take a volume that belongs to a consistency group and add it to a new consistency group, it will remove it from cg1 and place it in cg2 without warning. It gives the feeling the volumes belongs to two CGs and it also allows for a user to unintentionally remove the volume from its original cg and place it in a new cg without even knowing.

There should be a check in place that will not allow you to add a volume that belongs to a cg to a new cg until you delete it from its original cg. We should raise InvalidConsistencyGroup telling the user to first delete the volume from the cg before adding it to a new cg.