You can use VMware vSAN datastores as target datastores when configuring replications. Follow the guidelines when using vSphere Replication with vSAN storage.
Because user-friendly names of vSAN datastores might change and cause errors during replication or recovery operations, vSphere Replication automatically replaces the user-friendly name of a datastore with its UUID, which is constant. Therefore, the UUID is displayed everywhere in the vSphere Replication user interface, though you selected a human-readable name during replication configuration.
Limits of Using vSphere Replication with vSAN Storage
For reasons of load and I/O latency, vSAN storage is subject to limits in terms of the numbers of hosts that you can include in a vSAN cluster and the number of virtual machines that you can run on each host. See the Limits section in the VMware vSAN Design and Sizing Guide at https://www.vmware.com/products/vsan.html.
Using vSphere Replication adds to the load on the storage. Every virtual machine generates regular read and write operations. Configuring replications on those virtual machines adds another read operation to the regular read and write operations, which increases the I/O latency on the storage. The precise number of virtual machines that you can replicate to vSAN storage by using vSphere Replication depends on your infrastructure. If you notice slower response times when you configure replications for virtual machines in vSAN storage, monitor the I/O latency of the vSAN infrastructure. Potentially, reduce the number of virtual machines that you replicate in the vSAN datastore.
When you stop a replication, vSphere Replication does not delete the replica directory at the target datastore. As a result, stale directories remain on VMFS and NFS target datastores, and unused namespaces remain on Virtual SAN and Virtual Volume target datastores. Because the maximum number of directories and namespaces on a datastore is limited, you must manually clean them up to free resources on the datastore. See Clean Up the Target Datastore After You Stop a Replication.