I have been running Hyper-V Replica in my house for a while now. A while ago I noticed that some of my virtual machines kept on going into a critical replication state. It took a while for me to figure out what was happening:
Can you spot the difference between the working virtual machine and the failed one? The failed virtual machine is replicating using the fully qualified domain name – while the working one is using the short network name. Looking at the event log for this virtual machine confirmed that something was going wrong with name resolution:
Now for a confession. I am a bit of a klutz when it comes to configuring name resolution. For this reason my initial thought was to just change my virtual machines to all use the short network name for replication. But there was a problem with this approach. When you perform a planned failover using Hyper-V Replica we automatically switch to using the fully qualified domain name.
So I bit the bullet and tracked down some colleagues who were able to help me sort out my DNS server – and once that was done Hyper-V Replica was rock solid again.