Exchange Server Virtualization Support Policy Summary

Monday, August 25, 2008
Microsoft released their Microsoft Support Policies and Recommendations for Exchange Servers in Hardware Virtualization Environments document this month. I reviewed the support document and summarized the salient facts here.
Exchange 2007 Virtualization

Host Requirements:
  • A hypervisor virtualization solution that has been validated by the Windows Server Virtualization Validation Program
  • Adequate storage space to accommodate the host OS and components, paging file, management software and crash recovery (dump) files
  • Storage space must be allocated for Hyper-V temporary memory storage (BIN) files, equal to the amount of RAM allocated to each guest
Guest Requirements:
  • Exchange 2007 SP1 (or later) deployed on Windows Server 2008
  • Cannot have the Unified Messaging Role installed
  • The total maximum number of virtual processors cannot exceed the twice the number of physical cores.Typically 2 virtual processors are required for each Exchange server guest, but use this as a baseline
  • Large mailboxes (1GB and larger) require the use of Cluster Continuous Replication (CCR)
  • CCR nodes must be hosted on separate physical host servers to provide true redundancy and high availability
  • Mixing physical and virtual nodes is supported for CCR and SCC environments
  • Exchange supported backups must be run from the guest
  • Both legacy backups (using ESE streaming APIs) and Exchange-aware software-based VSS backups (Data Protection Manager) are supported
  • VSS backups of the an Exchange guest is supported if the guest uses only VHDs (not pass-through disks)
Guest Storage Requirements:
  • Supports fixed size VHDs, SCSI pass-through and iSCSI storage
  • Storage must be dedicated to one guest machine. In other words, a pass-through disk must be dedicated to one, and only one, guest.
  • Guest OS must use a minimum fixed-size VHD of 15GB plus the size of virtual RAM allocated to the guest
  • VHD limit is 2,040GB (nearly 2TB) in Hyper-V
  • Hub and Edge Transport servers require sufficient storage for message queues and log files
  • Mailbox servers require sufficient storage for databases and log files
  • iSCSI storage using an iSCSI initiator within the guest is supported. This offers greater portability, but decreased performance
Not Supported:
  • Dynamically expanding VHDs are not supported
  • Snapshots or differencing disks are not supported
  • Virtualization high availability solutions, such as Hyper-V Quick Migrations, are not supported. Only Exchange aware HA solutions (SCC, LCR, CCR and SCR) are supported.
  • VSS backups of the Exchange guest machine's pass-through disk from the host are not supported
  • Storage should be hosted on separate disk spindles from the guest's OS
  • Use SCSI pass-through storage to host transport and mailbox databases and transaction logs
  • When using iSCSI storage, configure the iSCSI Initiator on the host and present it as a pass-through disk to the guest
  • Use dedicated NICs with jumbo frames and not bound to a Virtual Network Switch, Gigabyte Ethernet, and isolated networks for iSCSI storage
Exchange 2003 Virtualization

Host Requirements:
  • The hardware virtualization software is Microsoft Virtual Server 2005 R2 or any later version of Microsoft Virtual Server
Guest Requirements:
  • Exchange Server 2003 SP2 (or later)
  • Microsoft Virtual Server 2005 R2 Virtual Machine Additions must be installed on the guest operating system
  • Exchange Server 2003 is configured as a stand-alone server and not as part of a Windows failover cluster
  • Each guest must have only one CPU
Guest Storage Requirements:
  • The SCSI driver installed on the guest operating system is the Microsoft Virtual Machine PCI SCSI Controller driver
  • The virtual hard disk Undo feature is not enabled for the Exchange virtual machine
  • Consider adding a dedicated virtual network adaptor for Exchange Server backups
  • Create separate fixed-size VHDs for Exchange Server databases and log files and store them on separate physical drives on the host
  • Exchange Server performance should be validated before production by using the Exchange Server 2003 Performance Tools
  • Make sure that the host server is sized correctly to handle the number of virtual machines that you plan to deploy
  • Use a storage solution that enables fast disk access
  • Antivirus programs should be configured to not scan VHD files

1 comment:

  1. BTW, the virtualizaion support agreement is not expected to change for Exchange 2010.



Thank you for your comment! It is my hope that you find the information here useful. Let others know if this post helped you out, or if you have a comment or further information.