Review: Windows Server 2008 R2
- 12 March, 2009 08:30
The noisiest new feature in Windows Server 2008 R2 promises to be live virtual machine migration, as Microsoft seizes the chance to show that Hyper-V is closing the gap with VMware Infrastructure. But there are many reasons beyond server virtualization to take a close look at Windows Server 2008 R2. Important enhancements are spread across the board, ranging from IIS to networking to Terminal Services. There's even a story to be told about R2 and the upcoming Windows 7, which gains better virtual desktop integration and even secure remote access without requiring a VPN -- though the latter feature, called DirectAccess, requires the use of IPv6.
Of course, I don't want to sell the Hyper-V upgrade short (see the June 2008 review, " Microsoft's Hyper-V does the trick"). Hyper-V gains two important performance improvements, the first being that it now supports 32 logical CPUs (i.e., cores) on the physical host. Raising the CPU barrier gives large datacenters a better chance to virtualize some of their biggest CPU hogs. The second performance improvement is live VM migration, which allows you to move a virtual instance from one server to another with little to no service interruption. Users can stay connected and working while the move takes place. Although they may notice a small pause, the move will be almost completely transparent to them.
Besides filling a check box in Microsoft's server virtualization marketing chart, exactly how useful is live migration? How often would you need to move a virtual instance between boxes? Well, if you're looking at a situation where the current Hyper-V host is bogged down with too many instances or the VMs are fighting over system resources, you may find yourself moving some of them to other servers. If you don't need to schedule downtime for the task, so much the better.
There are other reasons to move virtual instances. For instance, say you are experiencing minor network errors. You might want to move some of the more important virtual servers to a host on different network segment while you're working out the bugs. And of course there's always host maintenance. The physical host for these Hyper-V VMs will need periodic maintenance, which quite often means a reboot. Even when performing network maintenance on a router, it could be beneficial to move critical instances to another host. As you can see, there are several cases where moving your virtual server instance to another host could be beneficial and reduce the strain on your users and your business. I suspect this could become one of the most important features to businesses with a high number of virtual servers.
Viva la Server CoreOne of the best features of Windows Server 2008 is Server Core. Server Core allows you to install a trimmed-down version of Windows that hosts only the features you need. These would be services like DNS or Active Directory with little else on the box. By installing Server Core for these types of key functions, you greatly reduce the surface area for attack and improve performance of those services. In R2, Server Core now supports .Net and IIS. The latter plugs a huge hole in the Server Core offering; if anything can benefit from a reduced attack surface, it's a Web server. Server Core allows you to run IIS without ASP.Net, which becomes an optional install. Supporting .Net on Server Core also opens up management by PowerShell, which is another leap forward. Now you can not only have your cake, but you can manage it too.
Page BreakIn addition to running on Server Core, IIS gets an upgrade with R2. IIS 7.5 is a point release that probably could have been pushed via some other means, but it has some nice new features nonetheless. For instance, Microsoft has created a number of PowerShell cmdlets for the automation of everyday Web server admin tasks, as well as some security management tools. Every IIS administrator will appreciate the ability to automate backups of IIS metadata and content. But for large hosting services, automating the creation and management of sites, applications, and security settings will resonate the loudest. Now they won't have to allocate human resources to set up new customers or risk the inevitable human error when deploying Web applications across multiple servers.
FTP not only lives, but receives a makeover in R2. Although it's a little disappointing to find that FTP is still so prevalent, it's clearly not going the way of the floppy. The good news is you can now configure IIS to support several FTP sites on the same IP address. This allows you to easily set up different FTP sites from your domain, each with its own security defined. FTP has also been extended to support IPv6 and SSL.
The domain in SpainWhen asking whether R2 is merely a service release, consider that it introduces a new functional level for the domain. And to take advantage of some of the new enhancements to Active Directory, your domain has to be running at this new functional level. Among these new enhancements, my favorites are those for joining a domain. You no longer have to manually join a domain during deployment; instead, you can create an answer file that setup will use to put the server on the domain. In fact, the computer doesn't even need to be physically connected to the network to join a domain. It can be joined during deployment and then become a configured member of the domain when booted. This functionality is essential for remote deployments, which are fast becoming the norm as companies continue to decentralize.
Another exciting enhancement is the new Active Directory recycle bin. I'm probably a little bit more excited about this than I should be, but it's very cool. When you delete Active Directory objects, they go into a recycle bin, where you can recover them later if needed.
In this release, Terminal Services takes on a new name -- Remote Desktop Services -- and some pretty cool new features. One of the most impressive is RemoteApp, which allows you to connect to apps installed on a server and run them as if they were installed locally. The connection is made through Remote Desktop Protocol, so it's not just a shortcut to the foreign executable. I find it unbelievably easy to publish applications through RemoteApp and use them on a client. In addition to single applications, you can publish entire desktops through Remote Desktop Services. In this scenario, the published applications show up on the user's client system as regular desktop items; the user may never even realize they're not local. Remote Desktop Services is really beginning to obscure the line between installed apps and serviced apps.
Page BreakSuper scriptingAn upgrade to PowerShell will also be released as part of R2. PowerShell 2.0 comes with dozens of new cmdlets as well as some significant new features. I'll only mention two of them, but they're the ones I consider the most important.
The first is remoting. PowerShell 2.0 will allow you to make remote calls to servers and run scripts just as if you were at the console. There are more use cases for remoting than I can count, but needless to say, it's big.
The other killer PowerShell 2.0 feature is transactions. This means you can specify that every step in a lengthy script completes or all of the steps are rolled back together. Here again, the use cases are countless, but imagine being able to write a script that performs a number of actions, and if one fails, all of them are rolled back, keeping your server or your data clean. This is the same functionality that DBAs have had in the database for years. Windows Server 2008 itself already made use of transactions with Transactional NTFS, but now PowerShell supports it and the sky's the limit.
Windows Server 2008 R2 helps complete the Server Core promise by adding IIS and .Net support, which in turn allows PowerShell to piggyback on these enhancements. Windows server consolidation efforts get a boost from Hyper-V 2.0 and its live VM migration, while Terminal Services shops will find some nice enhancements in Remote Desktop Services. Not everyone will benefit from IIS 7.5, or feel the immediate need to upgrade the functional level of their Active Directory domains. Finally, other benefits -- such as branch office caching and DirectAccess -- also require a move to Windows 7. Windows Server R2 will likely receive its warmest welcome from large service providers, other organizations with large Web farms, and enterprises with lots of virtual machines.