For every virtual machine in a protection group, Site Recovery Manager creates a placeholder virtual machine at the recovery site. You must identify a datastore on the recovery site in which Site Recovery Manager can store the placeholder virtual machines.
After you select the datastore to contain the placeholder virtual machines, Site Recovery Manager reserves a place for protected virtual machines in the inventory on the recovery site. Site Recovery Manager creates a set of virtual machine files on the specified datastore at the recovery site and uses that subset to register the placeholder virtual machine with vCenter Server on the recovery site.
To enable planned migration and reprotect, you must select placeholder datastores at both sites.
Placeholder datastores must meet certain criteria.
For clusters, the placeholder datastores must be visible to all of the hosts in the cluster.
You cannot select replicated datastores as placeholder datastores.