The service pack supports hardware virtualization technology from Intel Corp. and Advanced Micro Devices Inc., as well as Volume Shadow Services, which lets IT managers back up Virtual Server and virtual machines without the need to install backup agents inside the guest operating system. Active Directory integration and management features are inside as well.
New in SP1 is support for host clustering and support for Novell SLES 10 and Solaris 10 as guest operating systems, bringing the total number of guest operating systems supported in Virtual Server 2005 to 11.
SP1 also includes virtual hard disk mounting and has a Virtual SCSI fix for Linux guests to address issues with some Linux distributions inside a virtual machine on the emulated SCSI bus.
Virtual Server 2005 R2 SP1 has been in its second beta since August 2006.