VDI has a storage problem. Everyone knows it, and it's the primary reason the technology has failed to meet the deployment levels that supporters had hoped.
In short, too many desktop images end up competing for too few connections to available storage, leading to boot delays, latency and diminished productivity compared to the standard desktop experience. Of course, storage has long been criticized for its lack of speed compared to server and networking technologies, which is why enterprises were so quick to embrace solid-state technology once it made the transition from consumer- to professional-grade performance.
So it only seems natural, then, that solid state should come to the rescue of VDI, where it provides not only faster read/write performance over magnetic media, but can be placed closer to the server and thus avoid many of the I/O issues of traditional storage networking.
Indeed, the idea of a storage-less virtual desktop environment is the key driver behind a recent partnership between VMware, Atlantis Computing and GlassHouse Technologies. The trio has aligned the VMware View platform with Atlantis's ILIO Diskless VDI software and a new Stateless Reference Architecture from GlassHouse in an effort to employ server CPU and RAM for traditional VDI storage functions. Using local server memory, the system is said to lower costs of VDI deployments and improve performance by reducing boot times to a mere 12 seconds and application launch times to one second or less. The system supports up to 140 virtual desktops aboard a single Cisco UCS blade, provides upwards of 227 IOPS per desktop and cuts memory use per clone to 275 MB.
Already, Flash-based VDI is taking hold in academic and commercial organizations in the U.S. and Europe. The UK's Anglia Ruskin University recently deployed 1,000 desktops on a 3000 Series Flash memory array from Violin Memory, which provides 220,000 random IOPS in a 4k block — a 20-fold improvement over traditional SAN-based architectures. At the same time, the school reports a 60 percent to 70 percent power reduction over a standard Windows 7 PC.
In Rockville, Md., direct mail firm EU Services has installed a hybrid Flash array from Nimble Storage to boost its fleet of virtual desktops from 50 to more than 200, more than enough to meets its needs. In fact, Nimble Storage executives told Tech Target that close to 40 percent of its business comes now from VDI deployments as enterprises look for ways to support desktop images on multiple stationary and mobile client devices.
This is part of the reason why top VDI providers are working quickly to incorporate Flash into the platforms. In addition to VMware's work with GlassHouse and Atlantis, Citrix recently certified Nimbus Data Systems' S-class and E-class memory systems for both the XenServer and XenDesktop platforms. The pairing is expected to boost I/O by a factor of 50 even as it cuts power, cooling and other costs by 80 percent. The systems also scale to 500 TB, which should be enough for even the largest VDI deployment.
The three-legged stool of servers, storage and networking has existed largely intact at most enterprises for more than two decades now. However, modern challenges call for modern designs, and the fact is that traditional SANs won't be able to keep up with the demands of VDI and other developments without massive upgrades. Deploying server-side Flash in support of VDI may be a radical change in data architecture, but it seems to be the least disruptive move in the drive to handle increasing data loads while reducing costs in the data center.
And as users adopt greater mobility in both their professional and personal lives, they'll need VDI to access their desktops no matter where they are.