Over the past few weeks I have been busy deploying Exchange 2010.  Many of these deployments involved deploying Exchange 2010 on VMWare ESX environments.   In a previous post I mentioned how Vmotion and Exchange 2010 DAGs was not supported.  However, based on some testing I have changed my opinion of this approach.  Perhaps it is just a fluke and I would be interested to hear what everyone out there is experiencing but here goes.

When leveraging DAG on Exchange 2010 and the need to VMotion the server comes up there seems to be an issue with doing a migrate when the Exchange 2010 mailbox server is powered off for the Vmotion.  I have seen this occur at two separate client sites.  Power off the Mailbox Server, Migrate, DAG broken.  Got it?

Now, what I am seeing that if I leave the Passive node online and replicating the passive databases with the active node a live migrate seems to work just fine!  I have tested this twice now (which is why I don’t know if it is a fluke or not) and both times migrating the passive node while powered on and replicating caused NO problems.  I even went as far as to reboot the passive machine anticipating it to break, but nope, nothing!

So, I’m going to challenge the community out there to try this if you can.  Live migrate your passive VM Mailbox node and see what happens.  If you can, power it off and migrate and see what happens.  I seem to have the same occurrence when the VM is powered down and/or when the VM is powered on.

Either way, from my testing it appears that if you migrate while the DAG member is online (keep in mind I didn’t have any active databases running on the node) it seems to successfully migrate without any problems!

Let me know what your findings are, but this is great news!

**Update**  Microsoft has changed their Stance on vMotion and Live Migrate.  Both features are now supported on Exchange 2010 SP1.  I happen to find this out while at TechEd and did post it here: http://www.scottfeltmann.com/index.php/2011/05/18/microsoft-teched-2011-update-day2/