Windows Server 2012When backing up a disk on Replica machine, Replication health goes to warning/critical and replication goes to Error state on primary server. Additionally, during the backup interval the following events are logged in the Microsoft-Windows-Hyper-V-VMMS-Admin log:
On Primary machine:
On Secondary machine:
Windows Server 2012 R2On Windows Server 2012 R2, the replication continues without any state change and replication health will be normal. However, the following events are logged on the Secondary server:
For example: If a user starts backup, it acquires the lock on VM and doing so will make replication fail during the time back-up is going on. Depending on the number of cycles missed, replication health of the secondary machine changes to warning or critical and primary machine replication state goes to error state.
In Windows Server 2012 R2, Delta replication means only sending changes. Apply of change log is done asynchronously. This means that RPO of replica VM will be intact even when backup is going on. Hence you only see errors in event logs while replication health and state will be normal and replicating respectively.
For more information on Resync, refer to the following blog:
In Windows Server 2012 R2, replication continues normally. No explicit action is required from the user end. If user initiates Fail back after backup is complete, all the pending changes will be applied if user selects latest recovery point before Failover starts.
The following Powershell command will show the latest time at which changes were applied on Recovery side in case of Windows Server 2012 R2: