Virtualize unified messaging for Microsoft Exchange

You can formally run Microsoft's communication tools on any major vendor's VM -- as long as you observe a few key rules

For those of you running a voicemail system in addition to an Exchange 2007 or 2010 on-premises environment, perhaps you haven't heard the news. Exchange provides a voicemail system that can not only take the place of your voicemail but provide for a universal inbox that puts voicemail notifications right in your mailbox. It can also transcribe the messages using its speech-to-text engine and allows you to connect to your calendar, phone directory, and email through Outlook Voice Access.

Despite all these features, Microsoft's unified messaging is not being deployed as rapidly as you would expect. Although companies are deploying Exchange 2010 rapidly, for some reason they're not doing unified messaging at the same time.

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There are several reasons you might have for avoiding unified messaging:

  • You are afraid of learning all the new telephony aspects of the unified messaging role. But it is typically recommended that you use a telephony expert to handle that aspect of it, so IT is off that hook.
  • The existing telephone system works just fine, so there's no desire to change it.
  • You have interest in deploying unified messaging, but doing so would require additional purchase of hardware (like an IP-PBX or a VoIP gateway to tie into the legacy PBX), which might have you put off.
  • Or you may need additional server hardware because Microsoft has not supported virtualization for unified messaging, so in these tight times, that hardware purchase has delayed any unified messaging investment.

You can now scratch that last excuse off the list, because the Microsoft Exchange team has opened the unified messaging role for virtualization.

Of course, you could virtualize unified messaging before Microsoft's formal support of it -- I've been doing so for years, once Microsoft worked out some kinks in early versions of Hyper-V and in voice quality. It has worked fine for me in labs, in conferences, and even in production environments. It wasn't supported by Microsoft, but it has worked like a champ.

The reason for the lack of virtualization support (supposedly) was because unified messaging uses a third-party real-time collaboration stack, and its vendor didn't support virtualization. Apparently, that is no longer an issue. However, some key requirements remain for working with the unified messaging role and getting support from Microsoft:

  • You must run Exchange 2010 SP1.
  • You must install the unified messaging role on a 64-bit edition of Windows Server 2008 R2.
  • The unified messaging role must be the only role installed on that virtual machine. It may not to be combined with any other role on the same virtual machine.
  • The virtualized machine must have at least four CPU cores and at least 16GB of RAM.

You might think that you could run the unified messaging role on a Hyper-V virtual machine, as Microsoft only described Hyper-V in its best-practices document. But the Microsoft Exchange team has confirmed that you can run the unified messaging role on a VM from any hardware virtualization vendor that is part of the Microsoft Windows SVVP (Server Virtualization Validation Program); that includes EMC VMware and Citrix Systems. This is good news for those who want to deploy the unified messaging role in a virtualized environment -- and for those who've already been doing it without having full support.

Another unsupported aspect of virtualization and Exchange has been the lack of support for hypervisor-based clustering or migration. But now the Exchange team says that in Exchange 2010 SP1, support is provided for Exchange high-availability groups (DAG groups) and hypervisor-based clustering, high-availability, and migration tools: Tools that "move or automatically fail over mailbox servers that are members of a DAG between clustered root servers" are now supported.

We will no doubt see additional enhancements to the world of virtualization. Will these changes affect your role out of Exchange 2010? Are you planning on working with the unified messaging role in a virtualized or physical environment in the near future? Let your fellow readers know.

This article, "Virtualize unified messaging for Microsoft Exchange," was originally published at Read more of J. Peter Bruzzese's Enterprise Windows blog and follow the latest developments in Windows at For the latest business technology news, follow on Twitter.

Copyright © 2011 IDG Communications, Inc.