Desktop virtualisation not a money saver

Server virtualisation changed the data center and often saves a lot of money. Not so with desktop virtualisation, say experts, as CIOs are finding that virtual desktop deployments can cost more than they initially bargained for.

"We are finding that the desktop virtualisation projects based on full-blown cost savings are coming off the table," said Natalie Lambert, an analyst at Forrester Research, who wrote a study on why the virtual desktop will become the new corporate PC.

Why the change? The licensing costs and infrastructure upgrades often needed to make virtual desktops a viable alternative to PCs affect the cost savings equation, despite attractive potential savings in help desk support and desktop management. Thus, more CIOs are looking to make the case for virtual desktops based on their security and desktop management benefits, Lambert said.

Desktop licensing costs range from $US150 to $US250 per user or desktop to be virtualised, which is on top of the regular license fee for the application, said Ty Schwab, CEO and founder of Blackhawk Technology Consulting. On the application virtualisation side, there's usually a one-time fee of $2,000 to $5,000 for the application virtualisation studio or administration console needed to design, repackage and virtualise applications. There's also an application virtualisation licensing cost of up to $US150 per virtualised application, said Schwab, who has worked on roughly 200 virtualisation projects of various types.

Then there are infrastructure considerations such as network, bandwidth and storage optimization. "Some vendors are claiming you only need 30 kilobits of bandwidth per virtual desktop, but in reality you will need at least 100 kilobits of bandwidth per user to handle loads and spikes," said Chris Wolf, an analyst at Burton Group.

Storage costs in relation to a virtual desktop infrastructure (VDI) implementation may be massive. On a traditional desktop, buying a local disk may cost $US80 per terabyte, but in a VDI environment using a SAN, a gigabyte -- never mind terabyte -- will cost you $US10 a pop because a SAN has a lot of other components like a high-end disk array and cables, said David Payne, chief technology officer of virtualisation integrator and consulting firm Xcedex.

"You will have to figure out how much storage needs to be located on the enterprise disk, and oftentimes that means SAN storage," he said. "And that requires a SAN infrastructure and the network for that and relocating all the distributed data that is on cheap drives today, plus all the capacity measured in terabytes and gigabytes that needs to be moved into the data center."

Ways to reduce storage costs

But there are ways to reduce storage costs. Both VMware View and Citrix XenDesktop can generate a virtual machine (VM) from a single VM image, with all the other VMs generated made from differential files. "This can save upwards of 60% of your storage costs for VDI," said Nelson Ruest, a principal at consulting firm Resolutions Enterprises.

Also on the server side, CIOs should be looking at data deduplication to reduce disk consumption on the desktop side. "Disk consumption and how much disk you need behind [the solution] can be one of the biggest spends in desktop virtualization," Payne said. CIOs should be evaluating deduplication technologies, which could reduce disk requirements for desktop virtualisation by 70% to 85%, he said.

"That alone can save you six or seven figures, and that can make the difference between virtual desktops making financial sense or not," Payne said.

Virtual desktop pilots most common today

The majority of virtual desktop projects are in the planning stage, and experts believe most enterprises will remain in pilot stage for at least 18 months due to a number of factors, including that CIOs are waiting for the technology to mature. It also takes that amount of time or longer to figure out how switching to virtual desktops will affect IT operations.

"A lot of enterprises are saying they see the value of [desktop virtualisation]. We've seen PC desktop support cost reductions of 20% in some cases, but at the same time if you commit to desktop virtualisation, it's a five-year commitment from planning to deployment," Wolf said.

Projects that are getting off the ground quicker are in highly regulated sectors such as healthcare, financial services and insurance. "Companies that have a lot of compliance requirements are moving forward much faster, and on a larger scale because it's easier to make a business case around security," Lambert said.

With desktop virtualisation, there is less concern about lost data since most desktop virtualisation technology takes data off the endpoint and puts it in the data center. And if a company opts for local desktop virtualisation in which data and applications remain on the desktop in a bubble, the same security process can be used as with traditional PCs such as encryption and controlled network access, as well as disablement of USB drives. On top of that, IT can realize manageability benefits such as centralized patching and maintenance and disaster recovery and business continuity through the ability to easily transfer desktop images to another server, for example.

However, IT may need to change some processes to segregate virtual machines from the servers they're running on. There must be some interaction with the server since the VM gets its resources from it, but IT should have a firewall on the shared network to block interaction at the operating system level.

Still, such changes are small compared with the virtual desktops' security benefits.

"Virtual desktops create a more secure environment because you have centralized data that is easier to secure," Payne said. "There is a smaller attack surface and IT gets more granular control of how users get access to data."