Mark posted earlier about Exchange 2007 virtualization.
My goal is to extend that post with information on the MBX Server Role. Microsoft support virtualization of all roles but the UM Server role. With respect to virtualization of the MBX role it's important to configure HA options that don't combine Exchange availability options with Hyper-V virtualization options. In other words Microsoft doesn't support using CCR or SCC with Hyper-V quick migration. Both CCR and SCC are supported in hardware virtualization environments.
Virtualization snapshots are not application aware and can't be used with CCR for recovery.
Many hardware virtualization products allow you to specify the number of virtual processors that should be allocated to each guest virtual machine. The virtual processors located in the guest virtual machine share a fixed number of logical processors in the physical system. Exchange supports a virtual processor-to-logical processor ratio no greater than 2:1. For example, a dual processor system using quad core processors contains a total of 8 logical processors in the host system. On a system with this configuration, do not allocate more than a total of 16 virtual processors to all guest virtual machines combined.
Running Exchange 2007 SP1 in a guest virtual machine does not change the Exchange Server design requirements!!!!
The Exchange Server guest virtual machine must still be sized appropriately to handle the workload.
For details and guidance about sizing Exchange server roles, see:
- Planning Processor Configurations
- Planning Memory Configurations
- Planning Storage Configurations
- Sizing Client Access Servers
- Mailbox Server Storage Design
- Transport Server Storage Design
Supporting large mailboxes (for example, 1 GB and larger) requires the use of cluster continuous replication or hardware-based VSS solutions. Using hardware-based VSS is not possible in a hardware virtualization environment.
High Availability and Disaster Recovery Considerations
LCR, CCR, SCC, and SCR are all supported for virtualization environments.
Some hardware virtualization software includes features that support the clustering or portability of guest virtual machines across multiple physical root machines. For example, Hyper-V includes a clustered solution called quick migration, which combines Hyper-V host machines with Windows failover clustering. For more details about quick migration, you can download the Quick Migration with Hyper-V White Paper.
Choosing a High Availability Solution for a Virtualized Exchange Server
We recommend using the built-in Exchange Server high availability solutions for virtualized Exchange servers instead of hypervisor-provided clustering or portability solutions (such as Hyper-V's quick migration feature). The features found in Exchange Server (in particular, cluster continuous replication (CCR)) provide greater benefits than those found in hypervisor solutions that move virtual machines between physical root machines.
It is supported to deploy CCR or SCC using a combination of physical nodes and virtual nodes. As with all Exchange high availability configurations, you must ensure that all nodes are sized appropriately to handle the full workload during scheduled or unscheduled outages.
More info on virtualization for Exchange 2007 can be found on technet.