vSphere Replication is subject to some limitations when replicating virtual machines.
Replicating Large Volumes
vSphere Replication can replicate virtual machines greater than 2TB with the following limitations:
If you move a virtual machine with replicated disks larger than 2032GB to an ESXi 5.1 or earlier host, vSphere Replication cannot replicate or power on the virtual machine.
With ESXi 5.5 or later, vSphere Replication supports a maximum disk size of 62TB.
Full sync of very large disks can take days.
vSphere Replication must track changed blocks and can consume more memory depending on the amount of data written on the disk.
vSphere Replication tracks larger blocks on disks over 2TB. Replication performance on a disk over 2TB might be different than replication performance on a disk under 2TB for the same workload depending on how much of the disk goes over the network for a particular set of changed blocks.
Replication might consume more or less bandwidth depending on the workload and how it changes blocks on the disk during the RPO interval.
Shared Disk Support
vSphere Replication cannot replicate virtual machines that share vmdk files in this release.
Raw Device Mapping (RDM)
vSphere Replication supports replicating RDMs in Virtual Compatibility Mode. RDMs in Physical Compatibility Mode cannot be configured for replication.
vSphere Replication does not replicate virtual machine snapshot hierarchy at the target site.
Powered off Virtual Machines
You can configure virtual machines that are powered off for replication. However, actual replication traffic begins when the virtual machine is powered on.