When upgrading target VRAs, an administrator might want to avoid any interruption in replication. As such, the administrator may think it relevant to change the target VRA for VMs targeting the VRA to be upgraded. This is not necessary, as following the upgrade of a target VRA, the affected VPGs only go through a Bitmap Sync.
If the Change VM Recovery VRA feature is used to change the target VRA for VMs targeting a VRA to be upgraded from a target VRA with Zerto Virtual Replication (ZVR) 3.0 Update 1 - 5, to one with ZVR 3.1 or ZVR 3.1 Update 1, a code bug may be encountered, that will cause the local Zerto Virtual Manager (ZVM) service to crash.
ZVR 3.1 and ZVR 3.1 Update 1
If this bug has been encountered, and the ZVM service crashes, do the following:
Power off the VRAs that were involved in the Change VM Recovery VRA process.
Start the Zerto service on the local ZVM
In the ZVR GUI, delete VPGs, while preserving target disks, that were in use by the initial host in the Change VM Recovery VRA process.
Power on the VRAs.
Recreate the VPG using the preseed option. Note that you can use the import option in the Zerto Diagnostics utility on the ZVM to automate this process.
Note: It is not necessary to use the Change VM Recovery VRA process when upgrading a VRA. If the VRA is a source VRA, vMotion protected VMs to other hosts in the cluster to avoid a Delta Sync during upgrade. If the VRA is a target VRA, a brief Bitmap Sync will take place following the VRA upgrade.