VMotion and Exchange 2010, not supported

20 11 2009

This article is moved towards my new site:





12 responses

20 11 2009
Dennis Agterberg

Nice posting Kenneth. I have a little question. I don’t know anything about Exchange 2010 yet, haven’t had the time to look into it. But shouldn’t you bring a little more nuance to the blog head. Like Exchange 2010 with DAG not supported with VMotion? As I understand from the text you wrote it all has to do with MSCS.

23 11 2009
Kenneth van Ditmarsch


Yeah I guess you are right, I assume that you can also run Exchange 2010 without DAG (I’m actually not sure of that)

6 01 2010
Michael All

Good article! I’m doing a design right now for a customer that will be exactly the same as yours, for the most part, but with only three Exchange 2010 servers instead of five. With Database Mobility on Multi-Role Exchange servers (M/C/H) (such as your configuration) MSit does not support running Windows Network Load Balancing Services on a server with Cluster Services on it. The only mention I’ve seen so far from MS on this is that you should use a hardware NLB in this scenario. Is that what you’re doing here or are you using another type of solution to load balance the traffic to the CAS server interfaces?

Thanks in advance for your response!
Michael All

6 01 2010
Kenneth van Ditmarsch

Hi Michael,

Thanks! 🙂 I’m not the Exchange architect at the current project but I indeed know that they are using hardware loadbalancers. Next to that they are currently building a CAS array since in the first setup everything was redundant except for the Outlook Profiles that pointed out to either one of the CAS servers (which obviously created a single point of failure on that side 😉

17 01 2010
25 01 2010
Virtualization Short Take #34 - blog.scottlowe.org - The weblog of an IT pro specializing in virtualization, storage, and servers

[…] Exchange Server 2010 on VMware vSphere, be sure to read Kenneth’s article here about Exchange 2010 DAGs and VMotion. At least live migration isn’t supported on Hyper-V, […]

27 01 2010
Edward Walton

DAG’s aren’t required to install and run Exchange 2010. It is just an option to introduce some Hardware and mail database high availability and DR.

Edward Walton
Senior Technical Advisor
Softchoice Corporation

29 01 2010
Tim H.

Thank you for the article Kenneth.

Your article states that DAGs rely on Windows clustering. Just to be clear, MS states that although some components of clustering are still present, they have been integrated into the core architecture of Exchange 2010. The idea of a server level failover cluster is gone. Failover is now at the database level and there is no need to build a Windows cluster before installing Exchange and creating a DAG.

In my mind, this should render any recommendations – from VMware or othewise – regarding setting up MSCS in a virtual environment a moot point as it pertains to Exchange 2010 and database availability groups.

You are correct about Microsoft not supporting DAGs in a root clustered or vmotion/HA environment. See the section on Hardware Virtualization at http://technet.microsoft.com/en-us/library/aa996719.aspx.

Another thing that is often overlooked by both architects and customer’s alike is the 2:1 virtual to physical processor support limit imposed by MS. That means for a 2-way quad-core machine, you can have a maximum of 16 virtual processors across all VM’s on that host. I’m not sure if that limit is specific to just Exchange.

No snapshots and no thin provisioned VMDK’s either.

Tim Hollingworth
National Technical Lead – Systems
ePlus Technology Inc.

17 02 2010
Ståle Hansen

Hi Kenneth. I posted on the Exchange 2010 technet forum about this and asked if Exchange 2010 would be supported if we manually disabled a VM from participating in a DRS/HA cluster in vSphere Update 1.

Apparently its still not supported by Microsoft.

My question is what consequences it have when we run Exchange 2010 DAG and disable it from participating in a DRS/HA cluster. Is it just that MS have not tested it and will get supported later or it does not work and breaks the DAG.

What do you think.

17 02 2010
Kenneth van Ditmarsch

Hi Ståle,

I guess the only reason for this not being supported is the fact that MS hasn’t tested it.
In our site it’s running fine, Exchange Availability and Failover is designed from an Exchange perspective so “pinning” the mailbox servers to one ESX Hosts seems like a fair solution IMHO which works fine over here.
Whenever a ESX Host fails the Exchange Mailbox Server that resides on it will fail as well, which is covered by the Exchange Availability design as stated.


19 02 2010

Nice blog, i like it, its informative,
i will visit his blog more often.
i like your article specially about
VMotion and Exchange 2010, not supported


19 02 2010
Kenneth van Ditmarsch

Hi Samantha,

Thanks! I’m busy finding other subjects to blog about.

Stay tuned 😉


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