Hyper V Replica in one of my favorite features found in Windows Server. Hyper V Replica creates a mirror image of a virtual machine on to another Hyper V server for redundancy. Hyper V Replica is useful for disaster recovery and business continuity. The replicated image can be kept off site and enabled in case the primary image goes down.
Hyper V Replica can replicate VM’s over an IP based LAN or WAN, even over a slow link WAN! It does not require expensive storage arrays or specialized hardware. Two Windows 2012, 2016 or 2019 Server’s running Hyper V can replicate VM’s from one to another out of the box. This feature brings inexpensive disaster recovery and business continuity to both private cloud and small business computing.
Typical scenarios might be:
- Replicating VM’s from main office to satellite office and vice versa as a DR and/or business continuity solution.
- Replicating VM’s from main office to data center as a DR and/or business continuity solution.
- Replicating VM’s between two local servers for redundancy or business continuity.
To implement Hyper V Replica, you need two Windows 2012 servers running Hyper V roles.
To begin, open the replication configuration section of the Hyper V manager.
From the source server, right click on the Hyper V server and select Hyper V Settings.
In the Hyper-V settings, select replication configuration.
Begin by placing a check mark on enable this computer as a replica server and then enter the protocol, port and location settings.
Once finished, click OK. Next, log in to the target replication server and repeat the above process. Once you have finished the replication configuration on both the source server and on the target server, it’s time to enable replication.
To enable replication, right click on the VM in the source server and select enable replication.
You will be presented with the enable replication wizard. Click next.
In the enable replication window, select the Hyper V server that you want as the replication target and click next.
If you get a ‘Could not get configuration details of the specified server’ error, check to make sure that the firewall on the target server is turned off or has port 80 open at a minimum. Also check that the server is reachable by pinging both its NetBIOS name as well as its FQDN. Both pings should return the server’s correct IP address.
Verify the connection parameters.
Verify the VHD.
Select recovery history and click next. The initial replication method allows you to seed the replication image to save time. Unless you are seeding the initial replica set, choose send initial copy over the network.
Confirm your settings and click finish.
You can configure a virtual LAN network adapter by clicking on the settings button now or you can manually assign a virtual network adapter later through the VM settings.
That was easy, wasn’t it? The server’s replica VM will remain in an ‘off’ state until the primary (source) VM fails. When there is a failure in the primary VM, you can manually switch over to the replica server as a business continuity solution.
Check this post if you receive the error: Hyper-V failed to enable replication and Hyper-V failed to authenticate using Kerberos authentication.
To view replication health and status, log into the target server, right click on the virtual machine and select replication then view replication health.
You will see ‘pending initial replication’ until the initial replication completes.
