Virtualization, running a guest system on top of a host system, is gaining popularity quickly. In brief, this works by creating a virtual machine that is contained in one main file. A virtual machine program, like VMWare is then used to load this virtual machine, and it functions as if it were a stand-alone computer. The hardware that the guest OS sees is whatever VMWare virtualizes for it; which means that a virtual machine can move from physical machine to physical machine and never know the difference.


Here is what can be done with such a setup. Say you want to have a basic Windows desktop where uptime is critical. A few weeks ago, I had someone with a Windows desktop that fit this situation perfectly, except that for no apparent reason the machine blue-screened and never came back, so it ultimately needed a full reload, which kept the machine out of commission for several hours as the software was put back the way it was. So instead of installing the OS directly onto a physical machine, we can set it up as a virtual machine.


In doing this, we'd load Linux onto the desktop, and configure it to launch the virtual machine on boot; so that when the boot sequence is completed, the user gets their standard Windows desktop. The Linux host system is set to make a backup copy of the virtual machine each night by simply copying the one file that contains the virtual machine's
contents. In the case of major software corruption, a virus, mad spyware, or any other of the numerous things that can cause Windows to just completely fail, restoring the previous day's virtual machine and putting the system back the way it was now becomes a five-minute process, not four hours.

This type of recovery also works well for a server, but there are even more options there for an organization that may have multiple servers.

We'll get into those details next week.