The server-hosted, hypervisor-based approach that VMware and Citrix Systems use to deliver virtual desktops provides significant security benefits and the opportunity to use power-saving thin clients as an endpoint. But server-based virtual desktop infrastructure (VDI) comes with a hefty price tag in terms of networking and storage costs, said Simon Bramfitt, an independent desktop virtualisation analyst.
The Achilles' heel of [server-hosted] virtual desktops is bandwidth, and if they don't find a way around that, VDI will be toast.
CEODurable Data Corp
"If you don't need the highest levels of security and don't want to buy the infrastructure in the data centre, the workstation approach to delivering virtual desktops is very attractive," Bramfitt said.
In workstation-based desktop virtualisation, a virtual machine (VM) is typically installed on top of the desktop operating system, abstracting all of the desktop applications and data. This approach delivers virtual desktops to end users even when they are offline. IT administrators can manage desktop images from the data centre so they can still get the management benefits touted for server-hosted VDI.
While the server-based VDI technologies get a lot of attention, some companies delivering client-based virtualisation software have made good arguments for using their software as an alternative.
Wanova's approach to virtual desktops
Wanova Inc.'s latest Mirage workstation virtualisation software ranked as a finalist among the 29 products submitted in the "Desktop Virtualisation" category for the Best of VMworld Awards 2010 this month. IT managers said it solves the problems posed by server hosted VDI products.
Durable Data Corp. (DDC), a San Antonio -based virtual desktop hosting provider, uses both Wanova Mirage and VMware View to deliver desktops to clients.
The company started out using Terminal Services, but it needed something more effective and secure for remote access, said Robert Ross, CEO of DDC. He switched his shop to VMware View but experienced performance degradation when delivering virtual desktops to remote users via WAN.
In an effort to solve the problems posed by server-based VDI, DDC tested a trial version of Wanova's Mirage product and found that its approach improved network performance during remote desktop delivery.
"The Achilles' heel of [server-hosted] virtual desktops is bandwidth, and if they don't find a way around that, VDI will be toast," Ross said. "The [workstation virtualisation] approach was a huge revelation to us, because we assumed all the virtual desktops had to live in the data centre, and the bandwidth required to deliver the desktop was a huge issue."
Since Wanova installs Mirage directly on end-user devices, users get personalised desktops both online and offline with near-native performance, he said.
"This solved the offline issue [that server-hosted] VDI products have," Ross said. "Offline mode is primary mode as far as we are concerned because it's an important piece of the portability component."
Wanova's approach to virtual desktops is to create layers within the PC. A 1 MB file gets installed onto an endpoint driver and it integrates into Windows, so there isn't a need for a hypervisor. Then, an image of each user's personalised desktop is saved as in the data centre, where it is centrally managed.
The latest version of Wanova's software, Mirage 1.5, recently launched with support for Windows 7, a wizard to migrate PCs from Windows XP to Windows 7 over the WAN, and other enhancements. Wanova licenses cost $200 per seat, and a free, five-license evaluation version of Wanova Mirage software can be downloaded from the company's website.
Similar to Wanova, RingCube Technologies Inc.'s vDesk lives on the client and separates applications, data and settings from the operating system without the additional hypervisor layer.
Mike Prepelica, director of IT at Revere Electric, which provides electrical supplies in Illinois and Wisconsin, last year opted for RingCube's technology after comparing it against VMware and Citrix's virtual desktop products. He needed a way to deliver desktops to ad hoc telecommuting employees and salespeople, who are responsible for buying their own PCs.
Prepelica uses VMware to virtualise servers, but VMware View didn't include offline support when Prepelica needed it. But even now, he said RingCube is a better choice because it doesn't need the back-end footprint required by server-based VDI products, and WAN performance doesn't suffer. Without back-end infrastructure costs, the $250 per user license fee is reasonable, he said.
"We didn't have to do any upgrades," Prepelica said. "It was very straightforward."
The 200-employee company now delivers vDesk to about 50 remote employees. Users simply plug a USB stick into their PCs or laptops to install their own Revere Electric vDesk, which takes the burden of configuring desktops off of Revere's small IT department, Prepelica said.
In addition, vDesk users can personalise their virtual desktops and don't seem to notice a difference in performance. The only reason users know they're on virtual desktops is the extra steps to log on and start vDesk, he said.
RingCube recently launched a new version, vDesk 3.1, with improved mobility capabilities for accessing vDesk from anywhere. The feature, called MobileSync, compresses encrypted workspaces for better performance on mobile devices and is how RingCube differentiates itself from other workstation virtualisation providers.
The company also recently introduced vDesk 3.2, which provides hardware-assisted workstation virtualisation support with Windows 7 64-bit systems on Intel Core vPro.