Going Virtual
Thanks to the ability to create virtual machines (VMs), it is becoming far less common to need dual-boot machines today than in the past. Using VMs, you can run multiple operating systems (or multiple instances of the same operating system) on the same hardware at the same time and not need to reboot the system each time you want a different OS.
The hypervisor is a virtual machine manager—the software that allows the virtual machines to exist. In the Microsoft client OS realm, the built-in hypervisor is the Microsoft Virtual PC. Other options include VMware and Xen, which are two other well-known hypervisors.
There have been a number of virtualization-specific threats that have cropped up focusing on the hypervisor, but updates have fixed the issues as they have become known. The solution to most virtual machine threats is to always apply the most recent updates and keep the system(s) up-to-date.
An excellent white paper from Microsoft on desktop virtualization can be found at http://bit.ly/vKTROF.
From a networking standpoint, each of the virtual desktops will typically need full network access, and configuring the permissions for each can sometimes be tricky. The virtual desktop is often called a virtual desktop interface (VDI), and that term encompasses the software and hardware needed to create the virtual environment.
Virtual desktops are often used with remote administration, allowing a remote administrator to work on the workstation with or without the knowledge of the user sitting in front of the machine.
The resource requirements for virtualization are largely based upon what environments you are creating. The hardware on the machine must have enough memory, hard drive space, and processor capability to support the virtualization. You also need the software to make virtualization possible. XP Mode has been mentioned earlier in this chapter and is a free emulator from Microsoft that you can download and it supplies a pre-configured virtual machine, which is run in the Windows Virtual PC emulator (the hypervisor). A number of others are also available. In most cases, the motherboard and associated BIOS settings need no alteration to provide services to these virtual machines. Some of the newer virtualization products, however (such as Microsoft’s Hyper-V), require that the motherboard support hardware-assisted virtualization. The benefit derived from using hardware-assisted virtualization is that it allows the hypervisor (the virtualization product) to dynamically allocate memory and CPU to the VMs as required.
