In this post I will explain how you can use the test failover functionality of Hyper-V Replica to evaluate the infrastructural elements of implementing a business continuity plan (BCP).
Just like a backup, your disaster recovery (DR) business continuity plan needs to be tested. And just as with a test backup, you need to be able to test the technology elements, namely starting up the replica virtual machines and therefore their services, without any impact on running production systems and the operations of the business.
Hyper-V Replica has a built-in feature called a test failover that allows you to start up linked clones of your offline replica virtual machines on a selected virtual network (probably isolated) without impacting your production systems. These test virtual machines can be created very quickly, started up, used, and destroyed, making the technical elements of your BCP test very easy.
There also is a nice unintended scenario with test failovers: You can use this feature to not only test your BCP, but also to bring online a copy of production systems for testing and diagnostics. Maybe engineers need to test OS or service upgrades and document upgrade/rollback plans? Maybe service administrators or operators need to diagnose performance or health issues? A test failover allows you to bring online a clone of production systems for a realistic and isolated test lab.
There are two elements to the test failover. There is a test virtual switch on the replica host to allow the test virtual machine to have network connectivity but remain isolated from production services in the primary site.
The second element is creating the test replica virtual machine. This creates a clone of the replica virtual machine. The machine configuration is identical except for:
How a test failover works using a linked-clone process.
The first step is to prepare the networking for a test failover.
Not only is this approach quick to start up, but it also means that replication will continue uninterrupted – we wouldn’t want Mr. Murphy to cause a disaster during a BCP test and leave us hanging!
Configuring a virtual switch for test failover.
The test failover VM is created with a suffix of “- Test.” You can power up and use the cloned virtual machine, testing that services will be operational and data will be available. Note that this VM will use any configured failover IP address that is configured in the replica VM’s NIC properties. The replica VM will remain offline and accepting replication changes from the primary site.