The main problem with image-based desktop deployment is that most organizations find it impossible to rely on a single desktop image. Different departments often require completely different sets of applications, and separate images may be required for each department.
In addition, depending on the methods used to create the image files, differences in hardware could also come into play.
For example, when I was a network administrator at a large organization with about 25,000 desktops, we purchased new desktops on a daily basis. The supplier was required to adhere to a standardized hardware configuration. However, one day, someone changed the standard, and the desktops were shipping with a different brand of network card. As a result, the deployment images no longer worked because they didn't contain the necessary network interface card driver.
Today, hardware compatibility is less of an issue. Windows Vista allows you to create an image that can be deployed with little concern for the underlying hardware. (There are always going to be minimum hardware requirements and basic compatibility issues.)
However, many organizations still use older operating systems or imaging software that creates images that work only on desktops with hardware identical to the system the image was created on. These situations often cause organizations to create a library of multiple desktop images. Maintaining so many different images can be time-consuming, and IT staffers may have difficulty remembering when they should use each desktop image.
The first step in dealing with these image management issues is to accept that there is no such thing as a perfect image. For example, suppose you manually configured a desktop system, installed the necessary applications and deployed all of the necessary patches. Regardless of how much work you put into creating the image, it will probably be outdated in less than a week as new patches are released.
Deploying network desktops
If image management can be so cumbersome, then what is the right way to deploy network desktops?
The answer is whatever provides the desired results with the least administrative effort. There is no one-size-fits-all fix, but there are some techniques that can make desktop deployment easier.
One of the best ways to reduce the burden of managing desktop images is to combine desktop image management with other deployment techniques.
There probably isn't going to be one desktop configuration that every user in an organization uses, but some characteristics are likely shared by most – if not all – of the desktops. For example, maybe every desktop runs Windows Vista with Service Pack 1 and Microsoft Office 2007. If you can find common configuration aspects, then you can build an image to serve as the starting point for deploying new desktops. Although this image doesn't need to contain every application your users might need, it should contain the Windows operating system, a basic set of patches and applications common to all desktops.
Once the image is created, you could use group policies or a desktop management application such as Microsoft's System Center Configuration Manager to deploy more specialized applications. This technique ensures that these applications are applied only to the desktops authorized to use them.
When using this technique, keep in mind that not every application can be automatically pushed to network desktops. It is important to make sure that you won't need to perform any manual deployment steps.
A variation of this technique is hosting applications on a Windows Terminal Server. The Windows 2008 version of the Terminal Services includes a feature that allows applications to run remotely on the Terminal Server while providing the illusion that they are installed locally on the desktop. These remote applications are deployed to the desktop through a standard .MSI files created on the Terminal Server and can run side by side with applications that are locally installed.
If you start with a basic desktop configuration image containing any of the applications made available to everyone, it should be relatively easy to remotely host your remaining applications and then deploy those applications to the appropriate desktops by using group policy settings or desktop management software.
|ABOUT THE AUTHOR:|
Brien M. Posey, MCSE|
Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Exchange Server and has previously received Microsoft's MVP award for Windows Server and Internet Information Server (IIS). Brien has served as CIO for a nationwide chain of hospitals and was once responsible for the Department of Information Management at Fort Knox. As a freelance technical writer, Brien has written for Microsoft, TechTarget, CNET, ZDNet, MSD2D, Relevant Technologies and other technology companies. You can visit Brien's personal website at www.brienposey.com.
This was first published in September 2009