Deploying virtual desktops tends to be expensive, and achieving adequate performance can be a challenge. Since both of these issues are often related to the underlying storage infrastructure, some administrators address them by using storage virtualization. This article covers the pros and cons of using storage virtualization in a virtual desktop environment.
Storage virtualization isn't based on a single product or technology. Many vendors offer their own storage virtualization solutions. For the purposes of this article, I will define storage virtualization as a technology that places a layer of abstraction between the virtual desktop (or the underlying hypervisor) and the physical storage. The actual benefits achieved by using storage virtualization vary depending on which technology is being used. Some of the most common are reduced storage costs, higher performance and easier manageability. Of course, way in which such benefits are achieved varies widely from one product to the next.
One method to reduce costs by decreasing the virtual machine storage requirements is deduplication. Deduplication is well suited to virtual desktop infrastructure (VDI) because all of the virtual hard disk files used by the individual virtual machines (VMs) are typically identical, although an organization may maintain several sets of virtual hard disks. There are a number of different deduplication products on the market, and although they are all designed to conserve storage space, most do nothing to improve storage performance.