Datasheet

Virtualization Considerations 25
Second, if the processor doesn’t support virtualization, or the BIOS doesn’t support virtu-
alization, you won’t be able to use Windows XP Mode. However, you can still use virtual
machines.
Tradeoffs between physical and VDI environments VDI environments require more
resources. These include newer processors and more RAM. However, if the PC supports it,
the environment may allow you to remove another PC. I’ve worked in some environments
where users had to maintain two PCs—one to do most of their work and another for legacy
applications. Two PCs cost more to maintain than one; this includes more electricity and
more cooling power. Many companies consider VDI environments a “greener” alternative.
Network load considerations Most PCs will have only a single network interface card
(NIC). This NIC will be shared with the VDI machines. If the virtual machines are con-
nected to the network and have a lot of network activity, you may want to consider upgrad-
ing the NIC.
Disk space Windows XP Mode requires a minimum of 1.6 GB of disk space. If you start
adding additional virtual machines, you’ll find that they take significantly more. For example,
a Windows Server 2008 virtual hard disk takes about 6 GB with an initial installation, and
Windows 7 takes about the same. These are dynamically expanding disks, so as more is
installed or added to the virtual systems, they will take more and more space.
This can be critical if the virtual hard disks are stored on the boot or system partition. If
they are stored on one of these partitions, you should monitor disk space usage closely.
Using Virtual PC for Mini Labs
I’ve been using Virtual PC (VPC) for many years to create virtual desktops and even vir-
tual networks where I could test and learn different technologies.
As a simple example, when first learning Windows Server 2008 and Windows Vista, I was
running Windows XP as my desktop operating system. I created two VPC images—one
of Windows Server 2008 and another of Windows Vista. I was able to load these two sys-
tems, configure the server as a domain controller in a domain, and configure Windows
Vista to join the domain. I now had a mini-network with a server and a client.
One of the greatest benefits of this virtual setup is that if I crashed the system, I could
easily rebuild it and start over.
Similarly, that’s what I’ve created for this book. While I’m running Windows 7 on my PCs,
I also have a virtual network consisting of a virtual Windows Server 2008 server and
another of a virtual Windows 7 client. With the knowledge you gain from this chapter,
you can do the same thing.
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