With storage vendors paying close attention to virtual desktop infrastructure deployments, array vendor Nimble Storage and consultancy GlassHouse Technologies Inc. recently published reference architectures
The VDI reference architectures include guidelines for the required computing, server virtualization, virtual desktop infrastructure (VDI) software and storage infrastructure. The companies tested and validated the VDI systems for simplified and accelerated virtual desktop deployments.
Nimble and GlassHouse include VMware Inc.'s vSphere 5.1 server virtualization software and VMware View 5.1 virtual desktop solution in their reference architectures, as well as Cisco's Unified Computing Platform (UCS) B230 M2 blade servers. Each blade has two Intel 2.4 GHz Xeon processors, 10 cores, 256 GB of RAM, dual 10 Gigabit Ethernet connections and the Cisco UCS Fabric interconnect.
Nimble's architecture is designed for up to 1,000 simultaneous VDI users, and includes six Cisco compute blades and one infrastructure host blade. GlassHouse designed its VDI reference architecture as a single-host cluster, supporting up to 140 virtual desktops with two Cisco blade servers.
Nimble's VDI reference architecture
However, Nimble and GlassHouse's VDI storage components are different. That's no surprise, because Nimble is a storage vendor, while GlassHouse is a consultant firm that recommends, but does not sell storage.
Nimble based its reference architecture on its CS220G-X2 hybrid solid-state and spinning disk storage array. Nimble's architecture is designed for non-persistent, knowledge-worker desktops using 10 to 15 steady state IOPS. The entire design fits in 3U rackspace and costs $43 per virtual desktop.
"What this enables customers to do is get an off-the-shelf blueprint that reduces the amount of deployment risk, and gives them a fairly high density for the amount of rackspace,"said Radhika Krishnan, head of solutions and alliances for the San Jose, Calif.-based company.
The CS220G-X2 has 12 1 terabyte (TB) spinning disks for between 8 TB and 16 TB of total usable capacity with compression, as well as four 160 GB flash solid-state disks (SSDs). The CS220G-X2 has an available expansion shelf that scales its capacity up to 147 TB. Krishnan said users can customize the amount of flash in the array for higher or lower performance.
Krishnan also said users can utilize existing equipment to assemble the VDI system, and swap hardware components to suit their needs.
"The reference architecture document itself is prescriptive in terms of best practices and such, but in general, customers are free to pick and choose the model that works best for them," she added. "For a 1,000-seat reference architecture, this is the recommended configuration, but that doesn't mean that customers would not have the leeway to pick a different blade server model or a different Nimble array."
Nimble put the list price of the storage used in the architecture at $72,000, but indicated the street price would be closer to $43,000. Courtney Burry, VMware's director of solutions marketing, indicated the price for all of the included VMware software is $250 per concurrent connection.
GlassHouse Technologies' VDI reference architecture
GlassHouse was commissioned by VMware and Atlantis Computing Inc. to simplify a diskless VMware View deployment using only server CPU and RAM for compute and storage. Atlantic Computing's ILIO Diskless VDI software is installed on each physical VDI host and processes all storage I/O internally, and also executes inline deduplication of the virtual desktop images.
"The way that a diskless product works is that it actually turns server memory into a virtual data store," said Erwin Vollering, service director for virtualization for the Southborough, Mass., company. "So from a VMware perspective, it's as visible as any other data store. With this technology, IOPS is really no longer a limitation."
GlassHouse deployed each non-persistent desktop as linked-clone virtual machine with a 275 MB virtual data store.
The GlassHouse reference architecture supports between 120 and 140 desktops per blade server, and provides 227 IOPS per desktop. GlassHouse also said the VDI environment boots virtual desktops in 12 seconds on average, and requires just 2.5 minutes to boot 120 desktops.
While GlassHouse's architecture was specific to a non-persistent, diskless environment, Vollering said the Atlantis ILIO solution could be used with a SAN to store end-user data and provide a persistent end-user experience.
Vollering said GlassHouse is working on a similar reference architecture using Citrix XenDesktop.