One of the big questions that administrators will have to address when designing a private cloud is whether to use remote desktops or virtual desktops. Each approach has its own unique advantages and disadvantages.
Remote desktops are based on the use of Microsoft terminal servers. In a terminal server environment, users establish a connection to one or more centralised terminal servers. The user’s applications run directly on the terminal server rather than running in a virtual desktop environment.
The primary advantage of using remote desktops is simplicity (at least when compared to virtual desktops). Remote desktop environments tend to have fewer infrastructure requirements than virtual desktop environments, which translates directly into lower implementation costs.
Historically, the biggest disadvantage to using remote desktops has been application compatibility. In the past, many applications simply would not run in a terminal server environment. Over the years, most of these compatibility problems have gone away. Some applications still won’t run properly on a terminal server, but it is possible to use an application virtualisation solution as a workaround to the problem. Of course, doing so does have an impact on cost and complexity.
Virtual desktop environments (commonly referred to as VDI) make use of large collections of virtual machines running on top of hypervisors. VDI environments tend to be much more complicated than remote desktop environments.
In a VDI environment, administrators must manage large collections of virtual machines. Furthermore, a connection broker is needed in order to match in the user sessions’ two virtual machines. If not properly implemented, the connection broker can become a single point of failure or a major performance bottleneck.
In spite of its cost and complexity, virtual desktop environments do offer a number of benefits over remote desktops. For one thing, virtual desktops provide end-users with a familiar experience. When users log on to a virtual desktop, they normally interact with a desktop operating systems such as Windows 7 or Windows 8. Remote desktop environments, on the other hand, sometimes force users to use a server desktop.
Virtual desktops also allow for a far greater degree of personalisation. Because virtual desktops are based on large collections of virtual machines, it is possible to create multiple categories of virtual machines to service the various means of users throughout the organisation. For example, an administrator could create one virtual machine image for the finance department and a different virtual machine image for human resources.
Similarly, an administrator can decide whether to make virtual desktops persistent or non-persistent. In other words, a virtual desktop can be configured to begin every session in a pristine state, or it can be configured to maintain user state data from one session to the next, thereby acting as a personal virtual desktop.
The choice over whether an organisation should use virtual desktops or remote desktops largely depends upon the organisation’s needs. Virtual desktops generally offer a greater degree of flexibility, but do so at a higher cost than what might be incurred with remote desktops.
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Brien Posey is a freelance technical writer.