Microsoft Unveils "Viridian" Hypervisor, Extends Virtualization Roadmap

Updated: May 24, 2006

by Alex Woodie

Microsoft bolstered its virtualization strategy in three major ways at the Windows Hardware Engineering Conference (WinHEC) in Seattle this week. First, it surprised many when it revealed plans to ship advanced new virtualization software for Windows, a hypervisor codenamed "Viridian," within 180 days of the release to manufacturing of the next version of Windows Server, codenamed "Longhorn." The company also gave a ship date for System Center Virtual Machine Manager, formerly known as "Carmine," and announced its intent to buy desktop virtualization pioneer Softricity.

Microsoft isn't a newbie to the virtualization space, but it's not necessarily a leader, either. Three years ago the company acquired Connectix and repackaged its product, now called Windows Virtual Server, that enables a user to install multiple operating system images, including X86-compatible systems such as Windows, Netware, and Linux, on a single server, which drives up efficiency and drives down hardware acquisition and management costs. According to Microsoft, server utilization rates hover around 10 to 15 percent, with utilization rates of 5 percent not uncommon.

While products such as Virtual Server can cut down on server sprawl, they're somewhat limited in their capability compared to so-called "hypervisor" products that sit directly on the hardware. With a hypervisor, such as the one sitting between IBM's Power hardware architecture and its i5/OS operating system, users benefit from more advanced capabilities such as greater granularity of CPU and memory, sub-socket partitioning, and dynamic reassignment of logical partitions (LPARs). These are the types of capabilities Microsoft discussed at last year's WinHEC (see "Microsoft Working on New Virtualization Technologies for Longhorn").

Microsoft firmly committed to delivering a hypervisor layer for Longhorn in April, and yesterday it made a firm commitment to deliver a hypervisor for Longhorn, called Windows Server Virtualization, no later than 180 days from the release to manufacturing (RTM) of Longhorn. Currently, Longhorn's RTM date is slated to occur in the second half of 2007, although in actuality, the product is tied to the development of Windows Vista, the new desktop operating system, which was recently delayed to the first half of 2007. If Vista slips again, it will likely impact the delivery plans of many different products.

'Viridian' Built Into Longhorn

Microsoft showed off Windows Longhorn Server's new Windows Server Virtualization hypervisor during chairman Bill Gates' WinHEC keynote address yesterday. Jeff Woolsey, a lead program manager on the Windows Server team, demonstrated some of the capabilities that Windows Server Virtualization will provide, such as being able to add network adapters or re-allocating memory to Windows virtual machines, without requiring a re-boot.

The hypervisor will also bring Longhorn new virtual I/O capabilities, expand the per-virtual machine memory limit from 4GB to 32GB, and support up to eight processors per virtual machine, Woolsey said. "No other virtualization technology provides this functionality for Windows," Woolsey said.

Woolsey added: "This is also an excellent example of the integration between the Windows kernel and the Windows hypervisor and how we're providing our customers the best solution in terms of dynamic capabilities and performance," he said. " In short Longhorn Server has been built to take advantage of hypervisor-based virtualization."

In his new Windows virtualization team blog, Mike Neil, the team's product unit manager, explains the relationship between the hypervisor and the Windows kernel--and in turn the relationship between his team and the Windows team. "In many ways the hypervisor is like a kernel, it manages memory, schedules threads (virtual processors) and handles basic functionality of the system," he writes. "Thus it makes total sense that the VM team is a peer to the Windows kernel team in the core operating system division."

'Carmine' is Key

Microsoft also gave the "Carmine" development project a formal product name: Microsoft System Center Virtual Machine Manager. Microsoft describes this product as providing a "centralized, enterprise management solution for the virtualized data center." Microsoft expects to have the first beta of this product available within 90 days, and anticipates shipping this product in the second half of 2007, in the Longhorn timeframe.

System Center Virtual Machine Manager is being developed in parallel with the Windows Server Virtualization hypervisor, and will provide the interface for controlling the hypervisor, Gates said during his keynote. "That's being developed in parallel to this (to make) it simple to define policies about resources and performance and things like that and let you control a lot of these all at once," he said. "That piece is a necessary element that people sometimes miss when they think about how we're going to get this to all come together."

The Virtual Machine Manager will give Windows users the capability to manage their virtualization environments, no matter if they're running the current Virtual Server 2005 product, or if they're running the new Windows Server Virtualization hypervisor layer. Both forms of virtualization will be supported with Virtual Machine Manager, although the hypervisor will provide more capabilities than its older brethren.

Microsoft will also make efforts to help users migrate their Virtual Server virtual machine environments over to the new hypervisor environment in Longhorn. "As people make investments today in Virtual Server, and then migrate those to the hypervisor, they can maintain a common management interface" using the Virtual Machine Manager, says Bill Shelton, a group product manager for the Windows enterprise management division. "It's not a this or that. You can have them both running."

Softricity for App Virtualization

Another piece of Microsoft's virtualization strategy came into view when it announced its intent to acquire Softricity, a Massachusetts developer of virtualization software that can significantly reduce the overhead of provisioning new applications, loading them onto desktops, performing regression testing, and maintaining those applications over time.

Softricity's flagship product, called SoftGrid, has some similarities with Citrix and Microsoft's remote desktop protocol (RDP) in that each of the products stream desktop apps from a centralized server to a client or dozens of clients. SoftGrid differs because, when the user requests the application from their desktop, that application is streamed over the network to the client, where it executes in a virtualized space SoftGrid carves out on the desktop. The advantage is a barrier between applications and operating system images that helps avoid "DLL Hell" when applications conflict.

It's not exactly clear how Microsoft will put SoftGrid to use, but there are a number of possibilities, including integration with Windows Terminal Services, the System Center Virtual Machine Manager, and even Windows Live services. Negotiations are ongoing between the two companies.

In related news, Microsoft announced Virtual Server 2005 Release 2 Service Pack 1. This release will take advantage of new virtualization capabilities that Intel and AMD are building into their processors, and which should be available next year, as well as Microsoft Volume Shadow Services. Microsoft expects Virtual Server R2 SP1 to ship in final form in the first quarter of 2007.