Complete Virtual Server R2 SP1 Beta 2 Release Notes are included in the installer and provide important information and usage instructions for the new features. It is highly recommended that you fully read these Release Notes. After installation, the Release Notes can be located in the ‘Microsoft Virtual Server’ Start-Menu folder.
What’s new in R2 SP1 Beta 2

AMD Virtualization Technology (AVT) compatibility*
Virtual Server 2005 R2 SP1 includes support for AMD® Virtualization Technology. By default, hardware assisted virtualization is enabled if present. Support for AMD® Virtualization Technology can also be specifically enabled or disabled on a per virtual machine basis by toggling the "Enable hardware-assisted virtualization if available" option in the general properties configuration page.

Volume Shadow Service Support**
Volume Shadow Service provides customers with improved support for backup and disaster recovery. Instead of scheduling downtime for backing up each virtual machine individually, customers will now be able to take snapshot backups of physical machines that will in turn take snapshots of all the virtual machines on that physical host.

Offline VHD Mounting**
Offline VHD mounting now enables customers to view and manipulate the files in a VHD from the host OS. This enables administrators to easily deploy scripts and perform virus scans across VHDs without having to start each virtual machine.

Active Directory integration and management features
Virtual Server service now publishes its binding information in Active Directory as a Service Connection Point (SCP) object. System administrators can use this information to easily locate all instances of the Virtual Server service within an Active Directory forest.
* Installing Virtual Server on a computer that has AMD hardware-assisted virtualization support and uses an x64 version of Windows as the host operating system generates a bug check and shuts down the operating system. This occurs because x64 versions of the Windows operating system protect a critical system register that Virtual Server modifies to enable hardware-assisted virtualization. You can resolve this issue by installing a hotfix prior to installing Virtual Server. Please reference the Release Notes for further information.
** For detailed information on this feature and how to use it, please consult the Release Notes that are included in the ‘Microsoft Virtual Server’ Start-Menu folder after installation.

What was new in R2 SP1 Beta 1 (also in Beta 2)
Hardware-assisted virtualization
Virtual Server 2005 R2 SP1 includes support for Intel® Virtualization Technology. By default, hardware assisted virtualization is enabled if present. Support for Intel® Virtualization Technology can also be specifically enabled or disabled on a per virtual machine basis by toggling the "Enable hardware-assisted virtualization if available" option in the general properties configuration page. Users should refer to their system’s documentation on how to enable Intel® Virtualization Technology.

Virtual Server host clustering step-by-step Guide
The host clustering whitepaper is now included with Virtual Server. It is installed at: ~:Program FilesMicrosoft Virtual ServerHost Clustering.

Larger default size for dynamically expanding virtual hard disks
The default size for dynamically expanding virtual hard disks has been changed from 16 GB to 127 GB.

Virtual SCSI fix for Linux guests
Some users encountered an issue when trying to install certain Linux distributions inside a virtual machine on the emulated SCSI bus. The issue occurred most often with the Linux 2.6.x kernel. This issue has been fixed in R2 SP1 Beta 1.

Download:
Virtual Server 2005 R2 SP1 Beta2 (32-bit)
Virtual Server 2005 R2 SP1 Beta2 (64-bit)