Setup virtual machines

 

Virtual machines are a computer emulator in software. The CPU supports some of the needed features in hardware, so it is possible and efficient to virtualize a computer system. A virtual machine is a piece of software, which acts like a computer. It has virtual drives, which correspond to files on the disk, it reserves some memory for use by the virtual computer and so on. You can then turn on and off the virtual computer with the menu system in the virtualization program. You can also make snapshots of the computer and then later revert to this snapshot.

The drawbacks of using virtual computers are:

  • slower speed - nothing gets faster by being emulated.
  • degraded performance in gaming graphics and high-resolution timer applications.
  • high-performance CPU with lots of memory needed to run many virtual machines.

The benefits of using virtual computers are:

  • you only need one (1) physical computer and thus get a greener and more practical solution.
  • you actually get to use all 4 or more cores in your high-performance CPU.
  • you can easily try out various configurations and revert to snapshot and try something else - no need to reinstall every time.
  • you sometimes get better disk performance, because of caching issues.
  • and many more

Virtual machines come in several classes:

  • Commercial virtualization products are advanced and require advanced hardware.
  • Limited free versions of the commercial products are available so that a virtual machine can be run, but no new can be created.
  • Fully functional free virtualization products, which only lack the performance and management features of the commercial products.

The last category is interesting, because it enables virtualization on a desktop computer.

There are some concepts, which must be known

  • The HOST SYSTEM is the system on the physical computer, just like it was before you installed any virtualization product.
  • The GUEST SYSTEM is the system installed in a virtual machine.
  • A VIRTUAL DISK (Floppy, Harddisk or CD) is a file on the host system.
  • All virtualization products have their own formats for the virtual harddisk file, but conversion is possible.
  • A virtual floppy is an image file - a copy of all the sectors on the floppy
  • A virtual CD is an ISO file, which you would normally burn to a CD.
  • A virtual drive can be mapped to a physical drive, you can set the virtual machine to use the physical CD-drive.
  • Bridged network may just be the thing you need - or maybe a NAT network?
  • And more. Always read the documentation.

What do you need to get started?

  • A physical computer with lots of free disk space, a powerful CPU and lots of memory.
  • Installation CD or ISO file.
  • A virtualization product like Microsoft VIrtual PC or Oracle VirtualBox