Our Channel Explained series provides targeted articles that flesh out detail on channel terminology but avoid information overload. This week we examine the question, What is virtual desktop infrastructure?
By Yuval Shavit, Features Writer
Virtual desktop infrastructure (VDI) is a computer virtualization architecture, similar to server virtualization, that lets your customers virtualize users' desktops. Unlike virtualized servers, virtualized desktops need to interact directly with end users, so VDI involves a broader collection of tools, including technology to deliver the virtualized desktop as well as to create, host and manage virtual machines.
With server virtualization becoming more mainstream, companies that have already adopted it are starting to look into related technologies to further improve their efficiency. Desktop virtualization is one of the more common ones, and its underlying principle is very similar to that of server virtualization.
With server virtualization, a server's information -- including its operating system, configuration files, applications and any other data on the drive -- is converted to a file called a disk image. Virtualization software sets up an environment called a virtual machine (VM), which simulates a server's hardware and executes the disk image within that environment. The result is that the VM acts as if it were a physical server. Virtualization software can execute several VMs simultaneously, meaning that one physical server -- known as the host system -- can run several servers within it, each known as a guest.
VDI is similar, except that the guests are desktop OSes rather than servers. Depending on the deployment, the virtual desktop infrastructure may involve a user's laptop or desktop hosting that user's VM, or a central, back-end computer may host users' VMs and provide a mechanism for users to connect to their virtualized computers. Because disk images are just files, it's also possible to create a hybrid system in which a centralized server hosts employees' VMs when they're in the office, but each user can also run his or her own system on a laptop while traveling.
When desktops are centrally hosted, users often access them through a barebones thin client. Virtual desktop infrastructures can optionally include a connection brokerage layer that authenticates connections and dynamically assign users to VMs. This lets companies provision VMs and maintain enough for peak usage instead of total usage. VM provisioning can be helpful in environments like call centers, where employees work (and thus use VMs) in shifts rather than all at once.
Advantages of virtual desktop infrastructure (VDI)
As with server virtualization, one of the main benefits of centrally hosted VDI is hardware consolidation. Rather than buying fully functional computers for each employee, most of which will be underutilized most of the time, your customers can plan for overall usage on the server that hosts employees' VMs. And, since VMs can access a SAN attached to their host server, your client can consolidate on overall storage as well as CPU power and RAM. VDI can also be easier to manage, since IT departments can easily patch VMs on the host computer.
Virtual desktop infrastructure can also offer some security benefits, since a VM operates in its own sandbox, separate from its host. Employees often use their work computers for unrelated activities, such as browsing the Web, and IT departments would prefer to keep computers locked down to prevent malware from infecting the computer. On the other hand, employees prefer being able to control their computers and install applications as they see fit; these applications are often used for productive business work. VDI offers a compromise, since IT staff can provide a locked-down virtual environment within an unlocked computer. This environment would contain business applications and sensitive data, and would be protected from the rest of the computer. Since a VM's disk image can be encrypted, just like any file, this approach can also protect your client's data in case a laptop is lost or stolen.
