Overview❗
I am by no means a VDI expert, but it is a workload that serves a specific use-case in the IT space. this blog series will have two parts:
Discussing the need for VDI and why Nutanix belongs in the discussion
Focus on VDI solutions using Nutanix's Solutions Architecture documentation
Citrix Virtual Apps & Desktops on Nutanix
Why you need VDI 👏
Virtual Desktop Infrastructure, or VDI, is a way to provide end users with access to a virtual desktop or virtualized applications from any device. Why might a business do this? Consider this scenario:
A company hired fifty new contract workers, but the IT team doesn't want to provision each laptop individually and ship them (the contract is for six months). The provisioning process would entail asset management, software maintenance, and network/security configurations. If you've ever spent time waiting for your single personal laptop to finish with an OS upgrade, you know this can be a tedious process.
Instead of the IT physically provisioning these machines, VDI allows for the creation of virtual desktops powered by virtual machines (VMs) for the workers to log in at all times and from any device. VDI is enabled by creating a "gold image" VM serving as the base for all virtual desktops. After setting the gold image with the desired desktop experience and applications, the single gold image can be pushed to production, so the IT team only has to do one configuration instead of fifty; the virtual desktops will become full copies or link to the gold image. Each worker could then remote login from their personal desktop via a web browser or a connection point acting as a proxy server for authentication and authorization to the company's network--think Citrix Unified Gateway. Voila, VDI in a nutshell.
Could you see how much time and money that would save? No wasted shipping cost or man-hours putting Microsoft Word on a laptop, only to have those laptops sent back months later.
What is Nutanix?
Nutanix is a software-based company that pioneered the Hyper Converged Infrastructure movement. The company took the concept of three-tier IT architecture where the SAN appliance and network had become a maintenance burden and performance bottleneck, consolidating the SAN into one platform of software-defined compute, networking, and storage.
The benefits of central storage became local to the servers instead of have to do remote reads across a FC or iSCSI network. Furthermore, Nutanix HCI eliminated the need to create and assign LUNs, slowing down the process for developers to have ready infrastructure. I've never been a storage administrator myself, but I've heard horror stories of configuring volumes and LUNs for SANs. Quite frankly, if you could perform better with less hardware, why wouldn't you?
How Nutanix architecture improves VDI performance 🏃💨
Historically speaking, because of Nutanix's Distributed Storage Fabric, Nutanix fit the VDI workload exceptionally. In the early days of Nutanix, one of the first workload wins was VDI. Dheeraj Pandey, founder of Nutanix stated that of the first $100 million of revenue made, nearly 80% of it was made VDI sales. VDI success on Nutanix was because of a few core platform designs:
1) Data Locality - whenever a read I/O occurs, the data will always be local to eliminate reading across the network. If the data is not local, the data will be cached to be local or live locally in the extent store (virtual storage based in the HDD)
2) Storage Tiering - based on R/W patterns, Nutanix storage services will automatically tier data between the SSD & HDD (if using a hybrid cluster). This frees up SSD storage, allocating faster drives for virtual desktops
3) Redirect-on-Write Snapshotting - traditional snapshotting uses the copy-on-write technology which uses snapshot chaining, causing lots of degradation to R/W performance. Instead of those blocks having to be copied first then overwritten, Redirect-on-Write uses metadata to point to the original blocks and will write only new data as it comes along
4) Shadow Clones - the bread-and-butter of running VDI on Nutanix which in a multi-reader scenario, often used in linked clones, creates local caches copies (data locality) of the vDisk being read for the virtual desktops. This mean instead of all the virtual desktops reading from one vDisk on a different host, virtual desktops will be reading locally for improved performance
5) Deduplication - Nutanix natively suppresses zeros without enabling dedupe, aiding in increased capacity savings without the CPU overhead that dedupe causes. In the event of full byte clones, dedupe can be enabled for additional storage savings