You can upgrade vSphere Replication 5.5.x, 5.8, and 6.x to vSphere Replication 8.x.

To upgrade a previously installed version of vSphere Replication to vSphere Replication for Disaster Recovery to Cloud, you must mount the vSphere Replication ISO file on a system in your environment. The system must be accessible from the vSphere Replication appliance, and apply the update through the virtual appliance administration interface (VAMI) on port 5480. See Upgrading vSphere Replication.

After upgrading the vSphere Replication appliance, you must configure it to synchronize with an external NTP server. See Configure the NTP Synchronization in Your Environment.