Windows Hyper-V virtualization continues to make
inroads in the server virtualization market. Although Microsoft has had a
virtual server technology for several years, the features and
capabilities of Microsoft’s hypervisor virtualization poise Microsoft to
leap past rival virtual server technologies like EMC’s VMware. Windows
Server 2008 R2 was written to provide enhanced virtualization
technologies through a rewrite of the Windows kernel itself to support
virtual server capabilities equal to, if not better than, other options
on the marketplace.
Understanding Microsoft’s
Virtualization Strategy
Server virtualization is
the ability for a single system to host multiple guest operating system
sessions, effectively taking advantage of the processing capabilities of
a very powerful server. Most servers in data centers run under 5%–10%
processor utilization, meaning that there is excess capacity on the
servers that is unused. By combining the capabilities of multiple
servers, an organization can better utilize the processing power
available in the networking environment.
Some might suggest that
an organization should just put more users on existing server systems
to take advantage of the excess server capacity. From a load-balancing
perspective, however, most organizations prefer to not combine more
users on a single system, but rather have multiple systems distributing
the workload to provide some level of distributed processing. This also minimizes
single points of failure for an organization and provides distribution
of processing across multiple systems. Server virtualization can provide
server consolidation while still providing multiple physical host
systems to distribute the processing load.
History of Windows
Virtualization
Microsoft’s position in the
virtualization marketplace prior to the release of Windows 2008 R2
wasn’t one where Microsoft particularly had a bad product; it was
because Microsoft jumped into the virtualization space just four to five
years before the release of Windows 2008 R2 virtualization. Being
relatively new to the virtualization space, Microsoft had some catching
up to do.
Acquisition of Virtual
PC
Microsoft jumped into the
virtualization marketplace through the acquisition of a company called
Connectix in 2003. At the time of the acquisition, Virtual PC provided a
virtual session of Windows on either a Windows system or on a Macintosh
computer system. Virtual PC was used largely by organizations testing
server software or performing demos of Windows systems on desktop and
laptop systems—or in the case of Virtual PC for the Mac, the ability for
a Macintosh user to run Windows on their Macintosh computer.
Microsoft later dropped
the development of Virtual PC for the Mac; however, it continues to
develop virtualization for Windows systems with the release of Virtual
PC 2007. Virtual PC 2007 enables users running Windows XP or Windows
Vista to install, configure, and run virtual guest sessions of Windows
server or even non-Windows operating systems.
Microsoft Virtual
Server
Virtual PC, however, is
targeted at operating under an operating system that is typically
optimized for personal or individual applications, so Virtual PC does
not scale for a data center wanting to run four, eight, or more sessions
on a single system. At the time of the acquisition of Connectix,
Connectix was in development of a virtual server solution that allows
for the operation of virtualization technologies on a Windows 2003 host
server system.
Because a Windows
Server 2003 system provides more RAM availability, supports multiple
processors, and generally has more capacity and capabilities than a
desktop client system, Microsoft Virtual Server provided organizations
with more capabilities for server-based virtualization in a production
environment.
Virtual Server 2005
Although the initial
Virtual Server acquired through the Connectix acquisition provided basic
server virtualization capabilities, it wasn’t until Virtual Server 2005
that Microsoft had its first internally developed product. Virtual
Server 2005 provided better support and integration into a Windows 2003
environment, better support for multiprocessor systems and systems with
more RAM, and better integration and support with other Microsoft server
products.
In just two years,
Microsoft went from having no virtual server technologies to a
second-generation virtual server product; however, even with Virtual
Server 2005, Microsoft was still very far behind its competitors.
Virtual Server 2005 R2
Over the subsequent two
years, Microsoft released two major updates to Virtual Server 2005 with
the release of an R2 edition of the Virtual Server 2005 product and a
service pack for the R2 edition. Virtual Server 2005 R2 Service Pack 1
provided the following capabilities:
Virtual Server
host clustering— This technology
allows an organization to cluster host systems to one another, thus
allowing guest sessions to have higher redundancy and reliability.
x64 host support— x64 host support means that organizations
had the capability to use the 64-bit version of Windows 2003 as the host
operating system, thus providing better support for more memory and
system capacity found in x64-bit systems. Guest operating systems,
however, are still limited to x86 platforms.
Hardware-assisted
virtualization— New to processors
released from Intel (Intel VT) and AMD (AMD-V) are processors that
provide better distribution of processor resources to virtual guest
sessions.
iSCSI
support— This technology allows virtual
guest sessions to connect to iSCSI storage systems, thus providing
better storage management and storage access for the guest sessions
running on a virtual server host.
Support for more than 16GB
virtual disk sizes— Virtual disk sizes can
reach 2TB in size, thus allowing organizations the ability to have guest
sessions with extremely large storage capacity.
These capabilities—among other
capabilities of the latest Virtual Server 2005 product—brought Microsoft
closer to its competition in the area of server virtualization.
