In order to reap the benefits of virtual desktop infrastructure (VDI), network managers must first learn desktop virtualization network and storage best practices that include traffic prioritization,
load balancing and caching, as well as varying network designs for different desktop virtualization models.
The allure of desktop virtualization is that enterprises can save money by running a centralized abstraction of desktop workloads (operating systems and applications) on a remote server. This way, the IT team can give users thin clients—or bare hardware—that access these centralized desktop images. IT shops can then focus management and troubleshooting resources on the centralized server, as opposed to troubleshooting dozens or even hundreds of contained OSes running on laptops and desktops throughout the company. Desktop virtualization also enables multiple users to share the same laptops and desktops since thin clients can access secured, separate desktop images on demand.
However, providing VDI is a challenge for the networking team since the technology places serious demand on network and storage capacity. As a result, network managers must be creative in their architecture and management strategies. In this guide, we explore desktop virtualization network and storage requirements and implementation strategies.
VDI vs. desktop virtualization: Is there a difference?
VDI is defined as technology that enables hosting of a desktop operating system within a virtual machine (VM) running on a centralized server. Users may be geographically scattered but are all connected to the central machine by a proprietary local area network (LAN), Wide Area Network (WAN) or the Internet. VDI is a variation on the client/server computing model, sometimes referred to as server-based computing (SBC).
Desktop virtualization, on the other hand, can come in other packages. Some companies opt for streaming OSes from client devices. In this scenario, an IT shop might run Windows on a local client that can be accessed by other devices in the network. OS streaming works by performing a variant of the "network boot," where the client boots and mounts a desktop disk image from a server across the network.
Client-centric virtualization provides offline access to the virtualized desktop or sets of applications, while server-centric desktop virtualization requires online access. Some enterprises run a hybrid VDI in which users can work online, and then switch over to offline when they are ready to leave the office or hop on a plane.
Read more about the differences in desktop virtualization vs. VDI from SearchVirtualDesktop.com.
Desktop virtualization and VDI network challenges
Desktop virtualization might sound attractive, but there's a catch—users have no patience for delayed performance when it comes to booting up their machine and seeking a desktop image. When lag time occurs, the problem is often linked to a lack of network availability or increased congestion. If the network gets bad enough, users can end up waiting a long time even when selecting an application as simple as MS Word from the start menu. It's even more difficult to ensure performance when it comes to real-time applications like voice, video and collaboration.
Read more about desktop virtualization network challenges.
Desktop virtualization network requirements
Adding WAN bandwidth optimization and traffic prioritization techniques to the VDI network is one way to address the problem of latency. Using the WAN bandwidth optimization techniques of compression and caching reduces the bandwidth impact of VDI applications and improves response times. With caching, WAN optimization controllers can store images of frequently accessed desktops and application objects, so that they don't have to reprovision every time they are demanded by a user.
Read more about vendor tools and top strategies for battling VDI latency problems on the WAN from SearchEnterpriseWAN.com.
Video and unified communications only make VDI harder on the network
It's one thing to support a basic desktop image in a VDI environment, yet it's entirely different when video and unified communications are involved. Providing graphics alone is hard enough. There are a number of tactics to deal with when optimizing graphics, including distributed caching and load balancing of client and server processing.
Real-time communication is particularly sensitive to three issues: packet loss, latency and jitter. Management requires intelligence at both ends of the connection, something lacking on thin- and zero-client solutions. Therefore, bandwidth management from the server end of the connection becomes more important than ever. Experts suggest traffic compression, acceleration and prioritization among other techniques.
Read a full explanation of these network traffic management strategies that help battle VDI network capacity problems.
Desktop virtualization storage issues: What to consider
There is an unavoidable truth about desktop virtualization: Storage and users are separated across the network. This places demands on the network that differ by type of desktop virtualization and back-end storage strategy. Here are factors to consider when planning a desktop virtualization storage strategy:
- It is key to first understand the Input/Output (I/O) requirements necessary to support not just an OS, but each application you plan to support in your VDI implementation.
- Should you go with NAS or SAN to support your VDI environment? That will depend on the type of desktop virtualization you are implementing and how many connections you plan to support.
- Server-based and client-centric desktop virtualization place different demands on storage.
- When it comes to storage, it's crucial to understand intelligent caching and cloning to avoid latency in the network from storage to the user.
To fully understand the storage network requirements of desktop virtualization, read this SearchNetworking.com tip on desktop virtualization storage strategies. Also read more about planning for desktop virtualization storage requirements in this SearchStorage.co.uk tip.
Troubleshooting desktop virtualization environments
Troubleshooting virtual desktop network connectivity can be tedious because of all the variables involved in VDI infrastructure. However, it's a lot easier if you use a process of elimination to rule out as many potential problems as possible upfront.
In troubleshooting VDI environments, you will have to start with testing out connectivity problems at the laptop or desktop itself, and then move outward to testing server issues, network hardware performance and availability, and then storage connections.
Learn more about desktop virtualization troubleshooting techniques in this tip from SearchVirtualDesktop.com.
This was first published in April 2011