Executive Summary:
Windows Server 2008 R2 includes Windows PowerShell 2.0 and the latest version of Hyper-V, which supports Live Migration to move VMs between hosts. Core Parking adds improved power management, and support for 256 cores increases scalability. Other useful new management capabilities include Remote Desktop Services, a rebranding of Terminal Serivices with new functionality, remote sever management, and the Active Directory Administrative Center.

Although it seems like Windows Server 2008 was just released, Microsoft is already getting ready to deliver the follow-up release, Server 2008 R2. This release follows the cycle used for Windows Server 2003—the major OS release, followed by a minor R2 release. Server 2008 R2 includes a host of new management capabilities and functionality that administrators are sure to love. Look for a full review of Windows Server 2008 R2 coming soon to WindowsITPro.com and Windows IT Pro. For now, let's look at the top ten new features in Server 2008 R2.

10. 64-bit only—Windows Server 2008 R2 marks the first time that the Windows Server OS will be 64-bit only, meaning that Server 2008 R2 must run on x64-compatible hardware. Almost all of today's popular server hardware will accommodate this requirement, but the R2 release won't run on 32-bit systems.

9. Support for 256 cores—Improved scalability is another important feature in Server 2008 R2, which will be able to utilize up to 256 cores. This number is a huge jump from the 64-core limit in the original Windows Server 2008.

8. Core Parking—Windows Server 2008 R2's new Core Parking functionality enables improved power management. Core Parking lets the OS suspend cores that aren't in use, thereby saving the power required to run those cores. Parked cores can be reactivated in milliseconds to respond to increased workloads.

7. Remote Desktop Services—Another change in Windows Server 2008 R2 is the rebranding of Terminal Services to Remote Desktop Services. However, the changes aren't in name alone. The new Remote Desktop Services includes support for the Aero Glass interface, multiple monitors, and DirectX 11, 10 and 9.

6. New Hyper-V—A new Hyper-V release is included in Server 2008 R2. A prerelease version of Hyper-V was shipped with the original Windows Server 2008. R2 includes the latest version of Hyper-V. In this version, VMs are able to address up to 32 cores per VM, and the use of TCP Offload and Jumbo Frames provides improved networking performance. One of the biggest improvements in Hyper-V is support for the next item, Live Migration.

5. Live Migration—Probably one of the most anticipated features in R2, Live Migration improves VM availability by letting you move Hyper-V VMs between hosts with no downtime. Live Migration is Microsoft's answer to VMware's VMotion. Live Migration is built on top of R2's new Cluster Shared Volumes technology, which lets multiple cluster nodes concurrently access the same LUN.

4. Support for the .NET Framework in Server Core—One of the biggest disappointments in the original Server 2008 release was the lack of support for the .NET Framework in Server Core, which meant that technologies that seemed perfect for Server Core, such as Windows PowerShell and ASP.NET applications, couldn't run on Server Core. R2 fixes this problem by adding support for a subset of the .NET Framework that supports both ASP.NET and PowerShell.

3. PowerShell 2.0—Server 2008 R2 includes PowerShell 2.0, which features improved WMI cmdlets and support for running scripts on remote systems, creating ScriptCmdlets, and running background jobs. In addition, R2 has a new graphical PowerShell UI for developing and debugging PowerShell scripts. PowerShell 2.0 is compatible with PowerShell 1.0

2. Remote server management—Server Manager was one of the best improvements in Server 2008 because it provides a centralized and useful console for managing Windows Server. However, Server Manager is limited to working with the local system. With R2, Server Manager can be installed on network clients and can be used to manage remote Server 2008 systems.

1. Active Directory Administrative Center—For administrators, the biggest change in Server 2008 R2 is undoubtedly the new Active Directory Administrative Center, which replaces the older Active Directory, Domains and Trusts, Sites and Services, and Users and Computers management tools. The Active Directory Administrative Center is built on top of PowerShell and its actions are scriptable. One really nice feature is the new Active Directory Recycle Bin.