Posted by: Bridget Botelho
Citrix XenServer, Desktop virtualization, hardware, Servers, VDI, Virtual machine, Virtualization, virtualization costs, Virtualization management, Virtualization security, VMware, Xen
VMware Inc. Senior Director of Enterprise Desktops Gerald Chen visited our office on Tuesday morning to discuss the different types of desktop virtualization and answer common questions about Virtual Desktop Infrastructure (VDI), for example, how it differs from terminal services and cost issues.
Here’s how VDI works: each end user gets a virtual machine (VM) that is deployed from a server in the data center directly to a PC, laptop or thin client computer. Each VM is customizable, so all of the user’s settings are saved and re-booted each time the user signs in, Chen said.
When a user logs off for the day, their VM goes idle, and wakes back up when the user logs into their system again, according to Chen. Chen believes that the advantage of VDI is that sensitive data is not being stored on desktops, which can easily be lost or stolen, and these virtual desktops are easier to manage than physical ones.
“VDI is great for industries like health care that are really concerned about information security and compliance. The real value though, is in management. All of the information is safe in the data center, and centrally managed through Virtual Infrastructure,” Chen said. “For instance, if you have 100 new employees who need desktops, you can deploy a VM for each of them in just minutes, and manage all of them centrally.”
VDI is different from Sever Based Computing (SBC) systems like Citrix Systems Inc.’s XenApp in that VDI is connects a single user to a single operating system (OS), instead of having multiple users share one OS.
“Not every application likes to share an OS, and there is also bad isolation; if one application crashes, everyone sharing that OS crashes as well. Those desktops can’t be customized either. It is a locked environment.”
Chen went on to explain that with VDI, four to ten VMs per server core are supported, so a server with one quad-core processor can, theoretically, house 40 VMs. Of course, that varies depending on things like workload, applications and memory. If the VMs become too heavy for the server to handle, management features in VI3 intervene. VMotion can move live VMs from one server to another when capacity issues arise, as can Dynamic Resource Scheduler, which allocates and balances computing resources as needed using VMotion.
Desktop virtualization case study
As VMware announced customer case studies in February, including one at Huntsville Hospital in Huntsville, Alabama.
The hospital needed to implement a new medical information application throughout its network while protecting HIPAA-related data. Deploying hosted desktops on VMware, the hospital could lock down sensitive patient data and reduce the cost and complexity of desktop management.
They used combinations of thin clients and blade servers to access the centralized virtual desktops, and in turn, reduced power consumption across the hospital by 78%, improved longevity with lower hardware maintenance needs and made wireless thin clients on wheeled carts available to hospital staff. Also, doctors can remotely access their VMs through the Internet using a web browser when necessary.
The downside to desktop virtualization
While the benefits are clear, there are some downsides to desktop virtualization: extra storage and initial cost.
Chen told SearchServerVirtualization.com that VMware is working on reducing image sizes and has designed a way to keep only one copy of files that are identical among many users, like icons and other graphics, to reduce the amount of storage necessary.
The cost of implementing desktop virtualization turns users off. According to Ars Open Forum blogger ‘Bright Wire,’ the cost and the magnitude of system upgrades required is not worth the benefits.
“The cost of deploying virtual desktops is massive,” Bright Wire wrote. “You will need to re-gear your existing desktops to run the virtual or you will need vendor equipment that costs twice as much as a new desktop. Either way, the cost is big in manpower. On top of that, your infrastructure will need serious review.”
According to VMware’s product specifications, local desktop virtualization requires a 500 MHz or faster processor with recommended 256 MB of memory, though Forrester reports that PCs must be faster and have more RAM to work efficiently.
“In addition you need to look into the server infrastructure,” Bright Wire said. “You are talking about needing a lot of iron on the backside to handle the needs of the server to supply two to 16 desktops. All this adds up quickly and can easily swamp a datacenter.”
As for pricing complaints, VMware is used to hearing them and holds firm to the ‘you get what you pay for’ mantra, saying the management benefits are worth the price.
The company charges $150 per concurrent user plus additional costs for support, either Gold or Platinum levels. Both bundles include VMware Infrastructure Enterprise Edition for VDI (which consists of VMware ESX Server 3.5 and VirtualCenter 2.5) and the VMware Virtual Desktop Manager 2. The VMware VDI Starter Edition, which enables 10 virtual desktops, has a list price of $1,500. The VMware VDI Bundle 100 Pack, which enables 100 virtual desktops, has a list price of $15,000.
The market indicates a demand for desktop virtualization, as a number of other vendors also entered the desktop virtualization space including Sun Microsystems Inc., Citrix., Pano Logic Inc. and Symantec. Chen would argue that many customers come for reduction in hardware but stay for the management applications.
“Reducing hardware costs is not a reason to use VDI, it is management. We have customers who have seen 40% to 50% ROI in terms of management costs and the amount of time it frees up.”