An Interesting Use For Hyper-V Replica

I just saw a tweet that talked about using Hyper-V Replica for verification.  Huh?

Consider this: you have a production VM running.  You have a change control process that demands that you test upgrades and rollback plans to systems before you implement those changes.  Building new VMs can be time consuming – forget the template copy process – consider the time it takes to copy databases, install updates, and so on.

You could shut down the VM and copy it.  There’s some downtime there.  You could backup and restore the VM … just make sure it’s on an isolated network.

You could use Hyper-V Replica.  No downtime is required to get the copy running.  You can do the initial copy via removable (optionally encrypted) media if you need to do the test offsite, and use SSL authentication if the test environment is in a different AD forest/company.  Maybe you already have Hyper-V Replica in place and a cold offline replica of the desired VM exists on a host in the DR site.

Test Failovers will:

• Create a test copy of the replica VM.  This is very quick because it uses a differential disk linked to the VHD/X of the replica.  This means the replica remains unchanged, even if you make substantial changes during the test.
• Allow you to use an isolated test network.  This will fire up the test VM on a virtual switch of your choice, isolating the test VM from your production network.

Maybe you need to bring online multiple VMs via a test failover, including a virtual DC (WS2012 AD please!).

You can perform minor or major changes.  Maybe upgrade OpsMgr 2012 to 2012 SP1.  Maybe you’ll upgrade CRM and the backend SQL Server.  You can test/document the upgrade and the rollback plan (a contingency plan if all goes wrong).  When you’re done you end the test and the test VM copy (or copies) are removed, and you’re back to just having running production and offline replica VMs.