How to bake up Raspberry Pi thin clients for VDI
Raspberry Pis are one of the lowest-cost computing options out there, so it's only natural for IT to wonder whether they're suitable as thin clients for some enterprise use cases.
On the heels of Citrix releasing its own version of the Raspberry Pi 3 at Synergy 2016, IT should get ready for the possibility that these devices will become relatively common in the enterprise.
Raspberry Pi is a tiny single-board computer using a system-on-a-chip (SoC) made by Broadcom. They're typically used as low-cost devices in educational settings, but starting at just $35 each, creative people found additional use cases for them. Naturally, one of these use cases is as a thin client for a VDI.
In May, Citrix announced it had partnered with the Raspberry Pi Foundation to create a version of the Raspberry Pi 3 (RPi3) using HDX SoC technology to optimize XenDesktop and XenApp on RPi3 devices. The resulting product, Citrix HDX Ready Pi, costs $75 to $90 through hardware vendors ViewSonic and Micro Center, making it one of the most affordable enterprise thin client options. Citrix and even VMware shops will no doubt consider using Raspberry Pi thin clients -- if only because of the low cost of acquisition -- so IT should understand how to set them up to support VDI.
What is a Raspberry Pi thin client?
Raspberry Pi thin clients consist of circuit board about the size of a credit card with an HDMI port, Ethernet, four USB ports and a few other specialized connectors. They get power from a USB charger and run the Linux operating system. Apart from the size and price of these devices, the main difference compared to other Linux thin clients is that Raspberry Pi devices use a different type of CPU. The Raspberry Pi includes ARM CPU rather than x86 CPU like a normal PC. This limits the software that can be run on the RPi3 and requires customized software to get the best performance.
Usually, Raspberry Pi devices are sold as a bare circuit board and not a ready-to-use computer. IT needs to additionally supply a case, memory card, power supply, mouse, keyboard and screen to turn it into an actual thin client. Even with all of these extras, a Raspberry Pi 3 thin client is still a lot cheaper than most low-cost devices. IT should be able to assemble a full high-definition RPi3 thin client for around $200.
It is still early days of using Raspberry Pi devices as thin clients. There are a couple of custom Linux versions designed for thin client computing. Only one, ThinLinX's TLXOS, has a management console for configuring Raspberry Pis. The lack of choice here is the single biggest sign that RPi3 devices are not yet a primetime thin client option, but Citrix's support is likely a sign that the tide is turning. Right now, it's hard to recommend a VDI client device that doesn't provide IT with many management options.
Getting hands on with Raspberry Pi
I tested out a Raspberry Pi as a thin client in a VMware Horizon View environment. I used the Raspberry Pi Thin Client Project's Linux build found here. This project lets IT pros build and customize their Raspberry Pi thin client boot images. Administrators can add in client software and support for local printing, or remote support such as virtual network computing software. This isn't an end-user task, but with a bit of IT knowledge it only takes around an hour to get a reusable, working image.
I simply enabled Horizon Client and rebooted the RPi3. My Horizon View environment uses an SSL certificate issued by my own certificate authority. I had to tell Horizon Client to accept untrusted certificates, just as I did when I tested a Google Chromebook for VDI. With a bit more time, I could have added a CA certificate to the boot image on the Raspberry Pi, so that shouldn't be a problem for corporate VDI deployments that require certificates issued by a trusted authority.
I was able to get a desktop up on my full HD screen in a few minutes. The RPi3 is a good, medium-performance thin client. Microsoft Word and Outlook responded well inside the desktop. I was comfortable doing light web browsing and using my accounting software. The screen was not quite as responsive as when I used a Mac to access the same desktop, but consider that the Mac costs ten times as much. The performance and usability of the Raspberry Pi were similar to other budget thin clients.
Raspberry Pi thin clients are probably good enough for task workers who mainly use one application for data entry or customer support activities. This would also be a suitable thin client for shared or kiosk use, where people will only use it lightly or briefly and performance is less important than cost.
The biggest challenge of deploying Raspberry Pi thin clients is the lack of good support tools. I wouldn't want to have to manage the boot image on two thousand Raspberry Pis without some sort of policy-based management tool. So far there is only one tool to accomplish this and it looks fairly basic -- more suited to dozens of Raspberry Pis than hundreds.
Overall, Raspberry Pi shows promise as a thin client for use cases that are not demanding. It is certainly capable of running a Linux thin client operating system. The main impediment to production deployment is the lack of large-scale management tools.
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