Software license management techniques for the virtual data center

Software license tracking has not kept up with virtualization, posing problems for admins who may have difficulty understanding or following terms.

The approach that organizations use for software license management has remained largely unchanged for many years.

Typically, IT managers count on metering software to determine how many instances of software are installed. That number is then compared against the number of licenses purchased. While this approach has proven to be very effective, it is an inadequate method when managing software licenses for a virtual data center. This tip explains why conventional license auditing techniques are no longer acceptable when working with virtual data centers and the best alternative options for software license management.

Why traditional license auditing methods won’t work

There are two main reasons why traditional license auditing techniques don’t work very well in a virtual data center. One reason has to do with the rapid proliferation of virtual machines (VMs). Self-service portals have made it possible for administrators and authorized users to create large numbers of VMs in a matter of minutes. Often times, these VMs are transient in nature and are decommissioned (deleted) after a few weeks. This means that if an organization used traditional metering software to perform a software license audit, the audit results would likely be invalid within minutes of its completion.

Another reason why traditional software license metering techniques are inadequate for a virtual data center is because operating systems (OSes) tend to be licensed differently when virtualization is brought into the picture. In the past, an administrator needed a license for every OS that he or she deployed. Today, however, some Windows Server OSes come with multiuse licenses. For example, the Windows Server 2008 Standard edition can be installed on a virtualization host and on one virtual server (so long as the host-level OS is only used for running Microsoft Hyper-V). Likewise, the Windows Server 2008 Enterprise edition is licensed for installation on up to four VMs, and the Datacenter edition is licensed for an unlimited number of VMs.

This can be a big problem, because organizations rely on license metering software to determine how many licenses they need to purchase. If such an application is unaware of the fact that a license may not be required for every OS, then an organization could end up spending a lot more money than it needs to on software licenses.

Addressing server, application virtualization challenges

Another factor that can throw a monkey wrench into software licensing is application virtualization. Most software license tracking applications inventory each PC by looking at the system registry to see what applications are installed. This method of tracking licenses breaks down when application virtualization enters the picture, because virtualized applications are not installed in the traditional way. Therefore, the registry entries that are normally used to track software installations may not exist. Furthermore, some virtualized applications may not be installed at all. Some of the application virtualization products on the market stream applications to users' desktops rather than installing the applications directly on users’ desktops.

Unfortunately, there are no easy answers to the licensing challenges posed by server and application virtualization. Part of the reason for this is because many of the application publishers are still using legacy licensing terms that do not even address virtualization. For example, an application’s license might state that a license must be purchased for every computer on which it is installed. If the license does not specifically address virtualization, then there are several questions that can come into play, such as:

  • Must desktops be licensed if the application is streamed to them, because technically the software is not installed on the desktop?
  • If you are required to license each computer that contains a copy of an application, then does that mean you only need to purchase a single license for a virtual desktop infrastructure server that hosts 80 virtual desktops?

Resolving the software licensing dilemma

Software licenses can be cumbersome and confusing, and the terms may be difficult to follow precisely, but many IT pros will try to adhere to the spirit of the license terms. Even so, IT pros are still left with the burden of trying to figure out how to track software license usage in a virtual data center.

Although license tracking software meant for virtualized environments has not yet matured, using such software is presently the best option. Look for tools that are specifically designed for virtual environments and that understand the relationship between host servers and virtual servers. That is the only way that IT professionals can ever hope to properly license their server OSes.

As an IT professional shops for license metering software, they should also make sure that whatever product they choose has the ability to monitor license usage, either in real time or on a scheduled basis. That way, they can keep up with ever-changing software usage.

IT professionals that operate a private cloud, in which users can use a Web interface to create VMs on an as-needed basis, have several options to ensure license compliance. Their best option is probably to set quotas that are based on the licenses they own. That way, there is no danger of users exceeding the software license limitation.

Another option is to operate the cloud on the Windows Server 2008 Datacenter edition. That way, IT professionals don’t have to worry about how many virtual servers the end users create, since the Datacenter edition is licensed for an unlimited number of VMs. However, professionals will still have to make sure they properly license any applications that are running on those servers.

As you can see, there are no easy answers to addressing the challenges of properly licensing software running in a virtual data center. As license metering software matures, the problem should get better. In the meantime, your best bet is to take steps to prevent the over-proliferation of software installations.

About the author: Brien Posey is a seven-time Microsoft MVP with two decades of IT experience. During that time, Posey published thousands of articles and wrote or contributed to dozens of IT books. Prior to becoming a freelance writer, Posey served as chief information officer for a national chain of hospitals and healthcare facilities. He also worked as a network administrator for some of the nation’s largest insurance companies and for the Department of Defense at Fort Knox.

This was first published in October 2011

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