Windows Server 2008 R2 is a modest upgrade, but it's one that's worth paying attention to for organizations tracking Microsoft's foray into server virtualization--Hyper-V--as well as for companies looking to deploy Windows 7 in the short term.
With this R2 release, Hyper-V gains the capacity for shifting virtual machines from one host to another without interruption, a feature Microsoft calls Live Migration. Live Migration is an important addition, but Hyper-V has plenty of catching up to do with the better-established virtualization lineup from VMware, which has included support for migrating running VMs since 2003.
In particular, I find VMware's ESX Server simpler to configure and use than Hyper-V, both when manipulating a lone virtualization host and when controlling clusters of hosts. However, in the latter case, I've yet to try Microsoft's forthcoming Virtual Machine Manager product, which should smooth multi-host management.
Shipping in tandem with Windows 7, Server 2008 R2 is the first Windows server release to hit the market alongside a new Windows client in nearly 10 years. Microsoft has outfitted R2 with a handful of so called "better together" features intended to grease the upgrade skids for the pair of OSes.
These new capabilities include a means for providing Windows 7 clients with secure, VPN-less access to company networks via DirectAccess; with faster connections to file shares through BranchCache; and with enhancements to Terminal Services (now called Remote Desktop Services) sessions. eWEEK Labs will examine the Server 2008 R2/Windows 7 combo more closely in the near future.
Beyond the Hyper-V and Windows 7-related changes, R2 includes an assortment of smaller enhancements centered around managing remote systems, scripting administrative tasks via PowerShell, and reducing power consumption on physical and virtual machines running the OS.
Microsoft has not yet announced pricing details for Windows Server 2008 R2, but I expect that pricing will be similar to Windows Server 2008, which is available in five versions: a $999 Standard edition that comes with five CALs (client access licenses); a $3,999, 25-CAL Enterprise Edition; a $2,999-per-processor Datacenter Edition; a $2,999-per-processor version for Itanium-based systems; and a $469 Web server edition.
The changes that Microsoft has announced include the removal of all Windows Server 2008 SKUs shipping without Hyper-V, along with a CAL change in which Windows Server instances running only the Hyper-V role will not require Server 2008-specific CALs. What's more, Microsoft will be selling a new, Foundation Server SKU that will be bundled with OEM servers and is intended for small businesses with fewer than 15 users.
Starting with Windows Server 2008 R2, Microsoft is dropping support for the x86 platform while maintaining x86-64 and Intel Itanium 2 processor platform support.
I tested the x86-64 version of Windows Server 2008 R2 Datacenter Edition on a pair of HP servers--a DL360 G6 and a DL380 G6, which I used as Hyper-V nodes in a Failover Cluster configuration. I also tested R2 systems running domain controller and remote desktop services roles in virtual machines hosted from my Hyper-V pair.