With the introduction of Windows Azure Infrastructure as a Service in April 2013, Microsoft has effectively provided...
a new way to run Exchange. There are several factors to be aware of however, before actually doing so.
Azure IaaS -- also known as Windows Azure Infrastructure Services -- allows administrators to easily deploy Windows Server-based virtual machines in the cloud. While the platform is not specifically intended for use with Exchange Server, it does give admins a new deployment option.
Until this latest release, shops could only run Exchange Server on-premises or in the cloud via Office 365 or another third-party vendor. Think of a Windows Azure deployment as a middle ground between the two options.
Much like Office 365, Windows Azure allows for a cloud-based Exchange Server deployment. Unlike Office 365, however, Azure gives administrators nearly the same degree of control they have in an on-premises Exchange Server deployment. For example, Azure lets Exchange admins use third-party Exchange management applications. It also lets them use their own server naming conventions and infrastructure design.
As you can see, there are a few benefits to an Azure-based Exchange Server deployment. That said, it's important not to jump in blindly. First, review the four considerations below.
Exchange is not included in Azure IaaS
The first thing to understand if you're considering running Exchange on Azure is that Exchange Server is not included. When you create a virtual machine (VM) in the Azure environment, you're given a number of different templates to choose from. However, none of these templates include Exchange.
Because Azure wasn't created as a hosting platform for Exchange, there are currently no established best practices for running Exchange on Azure -- yet. In other words, you're on your own for the time being.
Also, Exchange Server licenses are not included in your Azure subscription. You must license Exchange separately.
Another important factor to consider is that because Exchange is not included with Azure, you shouldn't expect to contact Azure support with Exchange-related questions.
Accessing Exchange installation media
You must also figure out how you'll get the Exchange Server installation files to your virtual server. Unlike an on-premises virtual server, there is no option to connect to a physical DVD drive. Your only options are to download the installation files from the Internet or to map a network drive to a location containing the Exchange installation media.
In my experience, the easiest way to get the installation files to the virtual server is to copy the files to a cloud storage provider like SkyDrive, then download the files directly to the virtual server.
Exchange Server connectivity
Exchange Server must be able to effectively communicate with your instance of Active Directory. Therefore, you must establish a link between your local network and Azure.
After you do, it's a good idea to create at least one domain controller on Windows Azure. This domain controller can be a member of an existing on-premises domain, but you must define a separate Active Directory site since the Azure servers reside off-premises.
Compute resources and cost
The final major consideration for running Exchange on Azure is cost. Exchange Server on-premises costs are generally fixed -- aside from purchasing client access licenses. Similarly, Office 365 subscriptions use flat-rate pricing that is based on user count. Windows Azure is much different than both.
Windows Azure IaaS costs are based on resource usage. The exact billing formulas are complicated, but I can tell you that they're based on the number of the VMs you create, the size of the VMs and VM workload. That said, it's smart to begin with a small Exchange Server deployment prior to moving large numbers of user mailboxes to the cloud. Doing so should help you get a feel for what running Exchange Server in t
Not only does Microsoft enforce usage quotas for compute resources -- limiting the number and/or sizes of VMs you can create -- but storage (limited to five storage accounts) and Active Directory quotas (limited to 150,000 objects) are also factors to consider. You can read more about the usage quotas on Microsoft's Azure website.
About the author:
Brien Posey is a ten-time Microsoft MVP with two decades of IT experience. Before becoming a freelance technical writer, Brien worked as a chief information officer at a national chain of hospitals and health care facilities. He has also served as a network administrator for some of the nation's largest insurance companies and for the Department of Defense at Fort Knox.