Virtual Server 2005 R2 SP1 is a hosted virtualization solution that runs on top of the operating system, and Hyper-V is a hypervisor that runs under the operating system. Because this is a significant change in architecture between Virtual Server 2005 R2 SP1 and Hyper-V, there is no option to perform an in-place upgrade of a Virtual Server 2005 R2 SP1 to Hyper-V. Moving from Virtual Server 2005 R2 SP1 to Hyper-V involves migrating both the Virtual Server host and the virtual machines. The goal of the migration should be to get the Virtual Server host and virtual machines migrated with minimum impact and downtime. The best way to accomplish this is to migrate to new server hardware. This allows you to install Windows Server 2008 and the Hyper-V role or Microsoft Hyper-V Server 2008, configure the machine for the migration, and properly optimize the configuration following the guidelines provided in Chapter 7, “Hyper-V Best Practices and Optimization.” After you have optimized the installation, the virtual machines can be migrated from the Virtual Server 2005 R2 SP1 server to the new Hyper-V server.
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