Essential guide to desktop virtualisation
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In the early days of planning a VDI rollout, admins often focus on the back-end infrastructure necessary to deliver...
desktop services and give little consideration to the client endpoints. But IT needs to consider endpoints during the planning process to minimize maintenance, maximize performance and lower the total cost of ownership.
Although mobile devices have changed the virtual landscape in recent years, the toughest decision when it comes to VDI endpoints is still how to deliver desktops to users sitting at their desks. Administrators have three options: deliver the virtual desktops to existing PCs (thick clients), implement thin clients by purchasing dedicated machines or repurposing PCs, or provide users with zero clients.
Get to know the variety of hardware you can deploy for virtual desktop users so you can deliver solid VDI from the back end to the front.
Thick clients are in the house
A thick client is a basic PC configured to access the virtual desktop. The PC continues to run its own operating system and usually requires no significant hardware or software upgrades.
The easiest way to implement a thick client is to install the VDI client and add a desktop shortcut that connects it to the virtual environment. The user still has full access to the PCs native functionality with the added benefit of virtual desktop access.
Another approach is to lock down the PC's non-VDI components so the user can access only the remote desktop. With this method, the PC acts as a pseudo-thin client, but IT doesn't have to invest in new hardware, such as updated PCs or third-party thin-client endpoints.
For an organization full of usable PCs, thick clients are an attractive way to go because the company has already invested in the equipment and it's up and running.
Of course, the Windows OS running on that thick client means administrators have two environments to maintain for each user. IT needs to regularly patch and update thick client PCs and properly protect them against malware and other vulnerabilities. And the more access users have to the host system, the more time admins will have to spend managing and supporting those computers.
Thick clients can't take full advantage of all VDI has to offer, such as streamlined management, improved security, reduced hardware maintenance and reduced energy consumption. Fortunately, there are other options for VDI endpoints.
A dedicated thin client is essentially a downsized PC with a similar make-up but just enough processing power to run the VDI client. It provides few expansion or configuration options and usually runs only a lightweight OS such as Linux or Windows Embedded. Most of the processing is offloaded to the VDI server, so the device runs very little locally.
Since thin clients are solid-state machines with the OS locked down and only minimal access permitted to non-VDI components, these machines are inherently more secure than the typical thick client. Plus, thin clients can run without an internal hard drive or external media ports, which prevents users from downloading sensitive data to their local devices. It is rare that a thin client contracts a virus, particularly if it's based on Linux. No user data is stored locally, minimizing the damage that can be done if the device is compromised.
Thin clients can also reduce maintenance costs because they don't need to be replaced nearly as often as traditional PCs. The smaller footprint also makes them cheaper. They consume less power, are usually easier to implement and manage centrally and don't require the level of patching of a typical PC.
Another approach to thin clients is repurposing existing PCs to act like thin clients. IT can use a client conversion tool that strips out the old software, installs a lightweight OS and VDI client, and locks down the system like a thin client. This approach removes many of the maintenance and patching issues that come with a thick client. It also saves on up-front equipment costs and speeds up implementation, given that you're using PCs already in the office.
At the same time, you don't want to use a PC that's too dated, or IT could end up with more maintenance and equipment replacement over the long term.
Whichever type of thin client an organization chooses, it's important to note that these devices are still PC-like enough that they can support local applications and persistent storage. Some thin clients even come with extra PCI slots or external media ports. Although these features can be beneficial, they add to the complexity of managing the devices.
Organizations must also take into account licensing. The world of Windows licensing is complex, so IT needs to look at the licenses it has in place and what additional ones might be required. A switch to thin clients could end up costing an organization a bundle in unexpected licensing fees.
Getting down to zero
A zero client takes the stripped-down PC concept even further; it's a simple, lightweight machine configured with a standard set of features geared toward most users. The terminal serves no other purpose than to communicate with the VDI servers and render the virtual desktop. Like many thin clients, a zero client is built on solid-state technology that offloads almost all the work to the server. Unlike a thin client, a zero client does not run an OS. Rather, it is built with a specialized onboard processor specifically designed to handle a remote display protocol.
Because a zero client contains no hard drive, local storage or any other components that are not directly related to supporting VDI access, it is the most secure of the three options. Zero clients require little to no configuration, so they are quick to deploy, easy to set up, support centralized management, require few updates, and use less power than thick or thin clients. They also offer users a better video experience because the device can be tuned for a specific VDI protocol.
Still, thin clients are designed for a single protocol which means an organization can become locked into one vendor, making it difficult to accommodate changing desktop needs.
What should you choose?
When considering thin vs. thick vs. zero clients, IT should take into account the users' need for an authentic desktop experience and the amount of management these endpoints will require. It might appear that thin clients can provide a better long-term strategy over thick clients because they require less updating and replacements. But if a thin client goes down, administrators cannot simply swap out parts like they can a PC. They will instead have to replace the thin client altogether.
Of course, it's not an all-or-nothing decision. Organizations can use some PCs as thick clients and convert others to thin clients, plus purchase dedicated thin clients for some workers and zero clients for others. That setup does add management complexity, but it can be a good interim solution if some users still require the power of a full PC.
IT may also need to weigh if and when tablets might provide some users with their virtual desktop needs. For certain workers, such as those in the field or executives on the go, being able to connect to their desktops via their tablets can be a significant boost in productivity. Even so, many Windows applications are not conducive to touchscreen interaction, and screen sizes limit what users can do.
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