Multiple migplans per namespace is a new change for MTC 1.8.6

Before this change it was not possible to have more than one migration plan use the same namespace. If another migration plan tried to use a namespace that was associated with another plan, the plan would be rejected. This is because MTC was designed as a single shot migration tool. You migrate once and you are done. When we added virtual machines to the mix that can live migrate between storage classes this became an issue since we might want move the same VM more than once. Or if you have a large namespace with a lot of virtual machines for instance since I might want to only migrate VMs associated with a single application in that namespace.

Now it is possible to have multiple migration plans associated with the same namespace AS LONG AS they don't reference the same Persistent Volumes. This allows one to make plans for applications that reside in the same namespace or to do migrations in the same namespace in different steps if that is something you want.