There is a great whitepaper on TechNet comparing the power utilisation of native and virtual Exchange environments. With the recent announcement that virtualisation is fully supported for Microsoft Exchange, I know many customers that are considering it and some that were desperately awaiting it!
The whitepaper is called "Comparing the Power Utilization of Native and Virtual Exchange Environments" and it outlines a test methodology and power utilisation results for physical versus virtual Exchange environments.
Here is a snapshot of the results in WATTS:
This shows that the reduction of 8 physical servers to 2 physical servers (with a constant 32 processors) resulted in an overall 50% reduction in power consumption equalling around 8,582 kWh/year. This is equivalent to 6.2 tonnes of carbon emissions per year, equalling the carbon sequestered by around 1.4 acres of pine forest or CO2 emissions from 257 propane cylinders from your backyard barbie.
NB: This excludes storage, cooling and processor core consolidation.
There is some great data in this whitepaper - I highly recommend reading it if you are implementing Exchange and tossing up virtual Vs physical; or if you are looking for further power and cost optimisation opportunities.
On a slightly different but related topic, I was recently asked by a customer about using VMotion for HA/DR. If you are considering using VMWare VMotion, this is not yet a supported scenario. From the lips of our Messaging & UC expert here in Oz, Johann Kruse, below is a quick overview of the considerations for this particular area:
"We fully support VMWare as the virtualisation platform, but VMotion is not supported for Exchange Servers. If they do experience issues during a failover or outage, PSS/Premier would not be able to assist.
[As well as SCR] we recommend also using CCR for availability within primary site as it is fully application aware..VMotion is not application-aware, and using it can have unintended and unexpected consequences for a server application that maintains state data, such as Exchange.
There is a whitepaper from the product titled Microsoft Support Policies and Recommendations for Exchange Servers in Hardware Virtualization Environments at http://technet.microsoft.com/en-us/library/cc794548.aspx which I recommend.
Here is a comparison of CCR vs VMotion for availability....
|
Virtual machine migration |
Cluster continuous replication |
|
|
Operating system heartbeat detection |
Yes |
Yes |
|
Exchange server heartbeat detection |
No |
Yes |
|
Copies of Exchange data |
1 |
2 |
|
Requires shared storage |
Yes |
No |
|
Supports Exchange-aware backup from passive node |
No |
Yes |
"
