Last month I introduced you to Microsoft's new PC product, Microsoft
Virtual PC 2004. This week, we'll look at the server version of the
software called Microsoft Virtual Server. Microsoft Virtual Server,
similar to VMWare, allows you to run multiple operating systems in a
virtualized environment concurrently on a single physical server.
Virtual Server supports the virtualization of Windows Server 2003,
Windows 2000 Server, Linux, Unix and OS/2. The difference between these
two products is that Microsoft Virtual PC 2004 runs on Microsoft's
client operating systems (such as Windows XP), and can only support
client operating systems in the virtual environment. With Virtual
Server, you will need a Microsoft server operating system (such as
Windows 2003 Server) and can support the installation of server
The benefit to using a product like VMWare or Microsoft Virtual Server,
is that you can use a single physical server, and run multiple unique
instances of one or more operating systems on that machine. For
example, you could have a Windows 2003 Server running Microsoft Virtual
Server and install a separate Windows 2000 installation within the
Virtual Server environment. Within the Windows 2000 installation, you
migrate an existing Exchange 2000 Server installation to the "virtual"
Windows 2000 installation, and free up the hardware that was originally
running Exchange 2000, thus freeing up the hardware for a potential
upgrade to Exchange 2003.
You could also do some testing of a virtual Linux installation on this
same box to see how Linux could be of benefit in your environment
without having to buy a separate dedicated box. Of course, all of these
examples would require the host hardware to be beefed up with lots of
memory and processors, and possibly lots of disk space (depending upon
your needs). This is because each virtual instance of an operating
system requires the same amount of resources that it would typically
require if it were on a standalone machine. For example, if you
typically build your Windows 2003 servers with 1GB of RAM and your Linux
Servers with 2GB of RAM, you would need 3GB or more memory on your host
Microsoft Virtual Server so that you can allocate memory appropriately
to each instance.
From a licensing standpoint, each copy of a Microsoft Windows operating
system or Microsoft software that is installed on a computer running
Microsoft Virtual Server (or Microsoft Virtual PC 2004) must be
separately licensed. Additionally, each device or user accessing any
operating system on the virtual machine system requires a Windows Client
Access License (CAL) that matches the version of the most current
operating system running on the system (or later).
You can find out more about Microsoft Virtual Server at
Join me next week when I discuss the installation and configuration of
Active Directory Application Mode (AD/AM).