The block was initially created on excessSSD(rack r1),
storages[4](rack r3) and storages[5](rack r3) with
ONESSD_STORAGE_POLICY_NAME storage policy. Replication factor = 3.
Right after balancer moves the block from storages[5] to
storages[3](rack r2), the application changes the storage policy from
ONESSD_STORAGE_POLICY_NAME to HOT_STORAGE_POLICY_ID. In this case,
we should be able to delete excessSSD since the remaining