In a recent newsletter we introduced the concept of Application Delivery 2.0, a major component of which is virtualization. This is the fourth in a series of newsletters that discusses how we think that virtualization will dramatically shape 2010 and beyond. This newsletter and the subsequent newsletter will focus on the challenges associated with implementing virtualized desktops.
There is no doubt that there is more buzz in the industry surrounding virtualized servers than there is surrounding virtualized desktops. For example, our research indicates that whereas 8% of IT organizations have already implemented at least some server virtualization, only 50% of IT organizations have already implemented at least some desktop virtualization. That research, however, also indicates that within the next year that the number of IT organizations that have virtualized the majority of their desktops will almost double. In addition, the number of IT organizations that have not implemented any desktop virtualization will be cut in half. While cutting cost is the primary factor causing IT organizations to implement desktop virtualization, other key factors include increasing the productivity of the IT organization and having more control over the company's data from a security perspective.
Desktop virtualization centralizes the management of desktop applications including applications that are streamed on-demand to client devices (client-side virtualization) and applications hosted at the central site (server-side virtualization). In both of these models, the application is virtualized in the sense that it appears to be installed on the client device when that is not actually the case.
Client-side virtualization is comprised of two primary functions: application isolation and application streaming. Application isolation is based on the encapsulation of the application by an abstraction layer inserted between the application and the operating system of the client system. Application streaming is the process whereby the virtualized application is delivered to an end system's isolation environment from a centralized application repository over the WAN in an on-demand fashion.
When applications are streamed over the WAN it often results in some significant performance problems that require the deployment of a WAN optimization controller (WOC). For example, the code for streamed applications is typically transferred via a distributed file system protocol, such as CIFS, which is well known to be a chatty protocol. Hence, in order to effectively support application streaming, IT organizations need to be able to optimize the performance of protocols such as CIFS, MAPI, HTTP and TCP. In addition, IT organizations need to implement techniques that reduce the bandwidth requirements of application streaming. For example, by using a WOC it is sometimes possible to cache the virtual application at the client's site. Caching greatly reduces the volume of traffic for client-side virtualized applications and it also allows applications to be run locally in the event of a WAN outage.
The bottom line is that client-side virtualization increases the need for IT organizations to deploy a WOC. In our next newsletter we will discuss the impact of server-side virtualization. More insight into the changes we expect to see in 2010, as well as the drivers of desktop virtualization, can be found in Jim's recent report on cloud computing.