Review: Windows Server 2008 R2
This afternoon, Microsoft announced that it has finished the development work on Windows Server 2008 R2. The company released gold code to manufacturing, which means that customers, partners, OEMs and subscribers to TechNet and MSDN services will receive the code over the coming few weeks.
I have written extensive previews on a variety of aspects of Windows Server 2008 R2 during the beta and release candidate process. But now that the product is fully baked, in this RTM review I'll focus mainly on areas I haven't yet touched on, including Hyper-V 2.0, enhancements to Remote Desktop Services (also known as Terminal Services) and improved power management and power-use reduction.
Before I get into more specifics, though, let's step back and consider the whole package for a moment. Overall, I think Windows Server 2008 R2 provides a modest but interesting set of enhancements and upgrades over previous versions of Windows on the server. There are certain customers that will absolutely find this a compelling upgrade:
Companies that have an extensive investment, or plans a complex deployment, of Hyper-V-based virtualization. Hyper-V is now a very serious competitor to VMware -- and once you have purchased your Windows license, the price is unbeatable because Hyper-V is bundled into the server OS.
Firms that have vast swaths of Windows servers in data centers where space, power or both are becoming tight. The power-usage improvement can add up to serious savings. Couple this with the virtualization capabilities offered by Hyper-V 2.0, and Windows Server 2008 R2 staves off a very serious scaling and capacity problem for some companies.
Firms planning on deploying Windows 7 on a wide scale sooner rather than later. With Windows 7 and Windows Server 2008, you enable some scenarios that are truly useful, like DirectAccess and other services for Remote Desktop Services users. Of course there is considerable expense involved in going down this road, which puts this type of deployment out of reach of many businesses, at least for the moment.
Customers with older hardware and no plans to upgrade that hardware in this economic environment should put off any plans for R2, as it is a 64-bit only operating system. Additionally, while there are certainly notable and important upgrades and improvements to features in this edition, for a large number of customers there is probably nothing barn-burning about this release. Windows Server 2003 and Windows Server 2008 (the original version) were and will remain suitable for many companies.
With that said, Windows Server continues to get better and better. Here are a few reasons why.
Microsoft's initial release of Hyper-V, introduced with Windows Server 2008 in June 2008, was an attractive -- if limited in comparison to VMware -- entrance to the virtualization marketplace. Hyper-V lacked a live migration feature, scalability and some cluster integration features.
Now, with this version, Microsoft is so confident in the robustness of Hyper-V 2.0 that it placed the public Microsoft.com Web site platform on it, serving around 15,000 requests per second, over 40 million hits per day and over 1.2 billion page hits per month.
Arguably the most important inclusion in Hyper-V 2.0 is Live Migration. LM is, of course, Microsoft's response to VMware's popular VMotion technology, which allows you to move a virtual machine from one physical host to another with no down time -- a seamless transition from the perspective of your users. While the existing release of Hyper-V supported quick migration, there were a few seconds of downtime associated with the move; that has been removed. This is great for system maintenance scenarios: If you have a host that needs software updates or hardware maintenance, you can live-migrate VMs from that host to another -- all while keeping user connections and service up -- and then perform whatever changes or fixes are necessary on the now-unloaded host. Then, when done, you can migrate the appropriate VMs back, all without bothering your users.
One unheralded feature of Hyper-V 2.0 is the Cluster Shared Volumes (CSV) feature. Essentially, if you tried to set up a cluster using Hyper-V virtual machines in the original release, for each virtual hard drive (VHD) you had to carve out a LUN on your SAN where that VHD could reside. Since you would likely have 24 or fewer drive letters free, you could end up using Globally Unique Identifiers (GUIDs), those long and clunky alphanumeric identifiers, which could turn into a management disaster.
Enter CSV, which allows you to place multiple VHDs on a single LUN, while the VMs themselves still act as if each VHD is on its own LUN. All CSV volumes are stored in the ClusterStorage root directory, so navigating the different volumes is as easy as clicking through Windows Explorer or navigating directories in the command line.
Hyper-V 2.0 also supports up to 64 logical processors on the host computer and includes the ability to add to a running virtual machine (and remove them) without needing to reboot the OS on that VM. You can also dynamically allocate memory without any interruption of service. Finally, the processor compatibility feature allows live migration across different CPU versions within the same processor family (for example, Intel-to-Intel and AMD-to-AMD), but not across processor families. (VMware has the same limitation.)
Hyper-V 2.0, with all of its improvements, is what some customers have been waiting for before settling on Hyper-V for their virtualization solution. Hyper-V now offers feature parity with VMware's enterprise solutions in some scenarios.
In this day and age, power use is on everyone's mind. Windows Server 2008 R2 helps reduce and optimize power usage in most, if not all, situations; in all cases, savings can be achieved and realized simply by installing the operating system.
Perhaps the easiest savings to point to when upgrading to Windows Server 2008 R2 is in power management. In essence, on the same hardware with the same load factors, Microsoft claims R2 will present anywhere from 10% to 15% -- and sometimes even 18% -- power savings over Windows Server 2003 with Service Pack 2, without requiring any additional configuration.
The largest area of savings is on a server at idle load, thanks mainly to improvements in driver tuning and power management in hardware that can be used by the OS. However, even after loads begin to creep up, clever OS management features can maintain a significant reduction in power consumption. This is made possible through a rewritten processor power-management engine and enhancements to storage power management, among other features. Hyper-V 2.0 is also able to harvest most of these power-savings improvements, making the power story a compelling one for companies with data centers approaching capacity in terms of space and power.
Core parking is another interesting feature that intelligently detects loads on a system and prioritizes and optimizes the distribution of that processing workload among all of the cores available to the operating system. For instance, on single quad-core processor, core parking will enable modest workloads to be carried out only on one core and allow the remaining three cores to remain in a power-saving inactive state. When workloads become heavy enough to require the use of other cores, the OS "lights up" the other cores as necessary to handle the duties, and then returns them to the inactive state -- creating, in other words, a "bursting" of processor capacity.
The ability to detect power use and act on that is something new to Windows, and Windows Server 2008 R2 adds power consumption and budgeting information reporting features. Unlike some of the other out-of-the-box features, reporting and budgeting require the server hardware to play along. The hardware itself reports power information via the Advanced Configuration and Power Interface (ACPI) to the operating system, and Windows then exposes that information through Windows Management Instrumentation (WMI) -- including all plan and setting data. Whatever power plan is created can be administered remotely, and whatever existing power-management settings you may have in R1 also can be administered remotely.
Along with this comes the power budgeting feature, useful in certain scenarios where you want to cap the amount of power used by systems. Windows can intelligently control the power use of every device on supported systems, down to the device level in some cases, and establish a "governor" on power use that can be very useful in power-limited situations. For manufacturers, there is a Windows Driver Model (WDM) driver interface available for power budgeting.
Virtual Desktop Infrastructure
Originally called Terminal Services, the Remote Desktop Services (RDS) umbrella includes solutions for the new virtualized desktop infrastructure, or VDI. With VDI, you can deploy Windows Vista and Windows 7 to centrally managed virtual machines. This lets employees and contractors work in a consistent, managed environment from any location without a major investment in client hardware and the management difficulties usually associated with a remote scenario.
An important new feature of RDS is the new connection broker, which takes service requests from clients both on- and off-premises and connects them with virtual or real desktops, applications and anything in between. The broker supports virtual desktops that maintain their state on a per-user basis or that destroy themselves after each session. This is great for contractors, overseas employees and temporary workers who only need access to resources while engaged in their work. With RemoteApp, Web Access and RD Gateway services, the connection broker allows seamless access to both hosted desktops and applications. If you are considering application and session virtualization, this is worth a look; in the past, such capabilities required using a third-party solution like Citrix with Windows Server.
RDS also includes traditional Terminal Services features like Remote Desktop Protocol (RDP) and presentation virtualization technologies. There are also enhancements to the RDP experience, like multiple monitor support, enhanced audio support, Windows Media redirection, Windows Aero Glass support and enhanced bitmap acceleration.
RDP itself hasn't been left untouched. Efficient command remoting, which allows applications to use Direct3D to provide hardware accelerated graphics on the remote PC's graphics processor, reducing the need to transmit bitmaps, is employed where sensible, and bitmap remoting is used in other scenarios, making activities crisper and more responsive to users. The RDP compressor has been improved as well for both bitmap and command remoting, allowing RDP to consume less bandwidth than was used in both the XP (5.2) and Vista (6.0) versions of the protocol.
There are other parts of Windows Server 2008 R2 that we've covered before that also generate positive marks for the overall product.
DirectAccess may be the sleeper feature of Windows Server 2008 R2. It's the technology that sets up a VPN-less connection directly into your on-premises network through the magic of IPv6. Your users, in terms of their experience on their corporate laptops, no longer have boundaries between where they can work -- all resources on a network appear the same to them, whether they're in a hotel room, a hot desk in your branch office or a corner office downtown. The benefit of DirectAccess for enterprise administrators: It provides a remarkably easier way to allow your users to touch all clients, even those previously considered unmanageable.
The benefits, however, may be masked by the initial complexity and technological requirements needed to fully deploy DirectAccess. From IPv6 to the transition technologies to the very requirement that Windows Server 2008 R2 be running within the enterprise -- forcing you to be an early adopter -- I don't think anyone is arguing this is easy. But it's worthwhile, and its presence in the box is an exciting omen of "what could be" when it comes to perimeter-less networking.
In terms of Active Directory (AD), there is a new AD DS management console that features tight PowerShell integration, as well as an AD Recycle Bin that allows recovery of previously deleted objects. You can now join machines to a Windows domain offline, which is useful for branch offices and other connectivity-challenged environments.
The Windows File Classification Infrastructure, which was new to the first release candidate of Windows Server 2008 R2, is a robust property identification system that allows you to set up rules that assign values to files based on their location or content and then take various actions based on those resulting values. In a nutshell, file classification allows the business to manage data based on its value and sensitivity. You can set up rules that apply and enforce classifications to data stored on the network -- whether it's by file type, name, location or other criteria -- and you can then instruct Windows to automatically apply policy according to those classifications. Think of Group Policy for files.
With all these new features, R2 is certainly the best Windows Server operating system to date.
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Jonathan Hassell is an author, consultant and speaker on a variety of IT topics. His published works include a variety of books on Windows client and server, including Learning Windows Server 2003. His work appears regularly in such periodicals as Windows IT Pro magazine, PC Pro and TechNet Magazine. He also speaks worldwide on topics ranging from networking and security to Windows administration. You can reach Jon at firstname.lastname@example.org.