Virtualization has been a boon for multi-user systems, letting them run the Windows operating system and applications on servers. Each user’s state is saved as a virtual desktop that can be remotely accessed from PCs, laptops, netbooks, tablets, smartphones and even dumb “thin clients” (terminals costing as little as $200). The downside is that remote users of server-hosted virtualization need to be online to take advantage of the virtual desktop infrastructure (VDI)—a show-stopper for highly mobile workers.
That limitation has provided the motivation for a new paradigm: client-hosted virtualization.
“The world is moving more and more toward mobile personal computing, which is a problem for server-hosted virtualization,” said Terrence Cosgrove, principal research analyst at Gartner Inc. “Client-hosted virtualization is trying to solve that problem.”
The technology uses the native capabilities of the given platform—usually a laptop—to run programs that are synced with a binary image on a server but that execute on the user’s laptop, eliminating the need for the user to be online all the time. Intel, lobbying to get the IT community on board, is hawking client-hosted virtualization as a means of unlocking the native capabilities of mobile devices without sacrificing centralized control or managerial simplicity.
“Intel is building hardware virtualization support into its processors because there is tremendous momentum growing for client-hosted virtualization,” said Sham Sao, chief marketing officer at Virtual Computer Inc., which claims to be the first purveyor of client-hosted virtualization.
When using a device running a type-one hypervisor such as Virtual Computer’s NxTop, the user can run multiple OSes simultaneously and seamlessly switch between them. Here, the choices are two varieties of Windows and one of Linux. SOURCE: Virtual Computer Click on image to enlarge.
Intel is also ahead in hardware support for virtualization with its X86 processors. ARM is prepping virtualization support for the next-generation A15 Eagle core; by 2013, client-hosted virtualization will be possible on an A-15 processor running Windows 8. But analysts say it may take five years for ARM to catch up to the X86 in the sophistication of its hardware virtualization support. For now, that gives X86 processors a corner on the market for client-hosted virtualization, which Intel calls intelligent desktop virtualization (IDV).
“Virtualization often assumes that the delivery system is paramount, and that the endpoint can be anything you want because it is passive and uninvolved in the delivery mechanisms,” said Dinesh Rao, director of Intel’s independent software vendor program. “But at Intel, we believe the first principle of IDV should be ‘centralized management/local execution,’ where the endpoint is a co-equal participant in managing the user’s computing experience. (The two other principles of IDV are described in “Intel’s three tents of IDV,” page 3 of this story.)
Client-hosted virtualization runs apps faster than server-hosted virtualization, works with locally connected peripherals and eliminates the need for all the servers used in a server-hosted VDI. “For a server-hosted virtualization, you would need about 20 servers for 1,000 users, plus 50 terabytes of data storage and a network upgrade to handle the bandwidth,” said John Glendenning, senior vice president of worldwide sales and business development for Virtual Computer. “But with client-hosted virtualization, [for the same 1,000 users,] you only need one server for management and 2 terabytes of storage, and no network upgrades.”
Virtualization itself is platform-agnostic; it runs just as well on PCs as on servers. That allows client-hosted virtualization to offload the server’s tasks onto the laptops that mobile workers already carry.
Server-hosted virtualization users complain that the speed of their network connection becomes a bottleneck, nixing the advantage of having a laptop, which becomes little more than a dumb terminal. Proponents of client-hosted virtualization note that the technique offloads program execution onto the user’s laptop without the expense and networking complications of adding, say, one server per 50 users to the data center, and without compromising the laptop’s native speed.
“The word is getting out that there is an alternative to expensive and user-unfriendly server-hosted virtualization,” said Gartner’s Cosgrove. “The challenge will be convincing organizations to implement a new computing paradigm.”
RES Software’s hybrid desktop management works with Citrix's FlexCast technology to deliver virtual machines to mobile users; streamed on-demand apps; and traditional, server-hosted virtual desktop infrastructure. SOURCE: RES Software
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Virtual Computer’s NxTop hypervisor runs on each client laptop or desktop, with its
OS, applications and user state synchronized with a data center server.SOURCE: Virtual Computer Click on image to enlarge.
MokaFive’s management server distributes a golden image to Linux, Windows and Macintosh users running its LivePC hypervisor to allow cloud-controlled layered images, hot copy, self-recovery and automatic backup restore. SOURCE: MokaFive
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