After you have performed the rehearse operation successfully to verify the ability of your configured resiliency group to fail over on to the disaster recovery data center, you can use the rehearsal cleanup operation to clean up the rehearsal virtual machines or applications in the resiliency group. All temporary objects created during the rehearsal operation are now deleted.
A few examples of these temporary objects on Hyper-V servers are:
A separate copy of virtual machine when you use Hyper-V Replica for data replication.
A new registered virtual machine that has its virtual machine data files (VHDX) residing on snapshot LUNs when array-based replication (for example, EMC SRDF) is used for data replication.