VDI performance takes a nose dive when there aren't enough IOPS available, but there are a few technologies that breathe new life into an existing storage area network for a fraction of the price of adding spinning disks.
Now IT shops have one more option, and it undercuts the others on cost.
Liquidware Labs Inc.'s new Flex-IO software accelerates IOPS on virtual desktop hosts by using server RAM as primary storage. It's an approach provided by a handful of vendors today that costs far less than additional storage, industry experts said.
The cost of storage continues to be prohibitive, so anything that decreases that cost is a good thing.
Gunnar Berger, analyst, Gartner Inc.
James Gordon, first vice president of information technology and operations for Needham Bank in Needham, Mass., hadn't been able to deliver on the promise of virtual desktops until he freed up IOPS with Flex-IO on non-persistent linked clones in VMware View.
"I had been hesitant on the trigger because [virtual desktop] performance wasn't quite right," Gordon said. "Users could tell something wasn't right and we were getting those calls. That's when we knew we had to do something different."
Flex-IO installs as a virtual storage appliance and is administered from a central Web-based management console. Administrators can provision existing RAM storage to the Flex-IO virtual machine (VM) with 16 GB or more.
One Flex‐IO VM per ESXi host sits between existing storage and non-persistent virtual desktops. It uses the ESXi host memory cache to read and write IOPS and accelerate them. The result: a workload that could only perform at 600 IOPS can now perform at around 25,000 IOPS or more, according to the Flex-IO administration guide.
With Flex-IO, Gordon was able to repurpose existing server RAM to provide the IOPS users need.
"Our servers have 384[GB] of [RAM] so it was easy to allocate a quick 50 [GB] for a pool of virtual desktops," Gordon said. "Our images are about 26 [GBs], so we could put up to 150 non-persistent linked clones per host."
He benchmarked a non-persistent linked clone virtual desktop using Flex-IO against his personal virtual desktop, and it outperformed his machine by 100%, he said.
More ways to accelerate IOPS
There are other storage options to aid virtual desktop performance from companies, including PernixData Inc., Atlantis Computing Inc. and Fusion-io Inc.
The Atlantis ILIO virtual appliance, highly regarded by industry experts, provides additional IOPS and boosts VDI technology performance for persistent and non-persistent desktops. Fusion-io's ioVDI also does this for both types of virtual desktops.
Without these tools, companies are forced to throw more storage and a lot of money at the problem.
"If you need 60 [to] 80 IOPS per user, that may mean 100,000 IOPS for your environment," said Jason Mattox, Liquidware Labs' chief technology officer. "Your storage provider will want you to add more spinning disks … which can cost $50,000, and that's the solution that many use today. But they get sticker shock."
Most IOPS accelerators cost $5,000 to $6,000 per host, said Gunnar Berger, an analyst with Gartner Inc. in Stamford, Conn. In environments with 100 virtual desktops per host, that amounts to $50 to $60 per user.
Atlantis' ILIO Diskless VDI software for non-persistent virtual desktops, for instance, provides over 300 IOPS per user for a Capex below $200 per user, including the server hardware, RAM and Atlantis software.
The new Flex-IO tool comes in lower at $3,000 per host. In an environment with 100 users per host, that amounts to about $30 per user.
"At $3,000, it's a no-loss investment that is up and running in 20 minutes," Gordon said. "We are a small shop and I couldn't see body-slamming my budget by spending what I would for a server on a [Fusion-io] card."
Using server RAM is far more economical than investing in a storage area network, regardless of the price per host.
"The cost of storage continues to be prohibitive, so anything that decreases that cost is a good thing, as long as it delivers," Berger said.
Meanwhile, lower-cost hybrid storage is also being used with VDI, and flash cards have emerged. But flash and solid-state drive options still amount to a couple of hundred dollars per user, so utilizing spare server RAM is more cost-effective, according to Christopher Green, vice president of IT infrastructure systems for Washington Trust Bank in New England. He uses Atlantis Computing's Persistent VDI 4.0 software with VMware View.
Liquidware's Flex-IO software supports non-persistent VDI that runs on VMware ESX/ESXi Server, including VMware Horizon View and Citrix XenDesktop. Limited time lower introductory pricing is available in some regions and is available from the website to download and trial now.