Dear Tux Lovers,

Am a newbie to linux though am finding it interesting by the day, but I really need to understand more about virtualization and how it can help me run various operating systems at the same time or alternatively.

No help is little. Thanks

Well I'm not sure what you really want us to tell you here. It sounds like you really need to just generally read up on what virtual machines, http://en.wikipedia.org/wiki/Virtual_machine

Within Linux you'd be looking at VMware, Virtualbox or Xen to run virtual machines.

If you want to know your options for virtulisation on linux (with another OS inside the VM), the two big players in this area are Qemu (did I spell that right?) and VMWare.
Qemu is fully open source but can be a dog to install (I've beat my head against it more than once) there are a lot of people who have it working without any config, so maybe I'm an exception.
VMWare is commercial software that runs in linux, and you have to pay for the full version, but you can get a thing called the VMWare player for free. You can't create VM with the free version, but you can download premade virtual appiances from their website (then format them and install what you want)

If you want to run linux in a virtual machine (say on windows, but you don't want to dual boot). Your options are similar as both Qemu and VMWare are available for windows as well.
As for which disros run best in Virtual machines I personally have had the most success with Debian (but you do need special network divers to run the virtual network), but most of the stories I've heard are about fedora or RedHat working well inside VMWare

For linux, probably VMWare and XEN are your best bet. You can download VMWare server for free and try it out. XEN comes with CentOS, just enable the virtualization package during install and you are good to go.

I personally haven't played with Qemu, heard its a pain to install as well.

I have excellent results with Virtualbox http://www.virtualbox.org/
VMWare Player is very good too.

Am I missing something? I just did a CentOS 5.2 DVD (32 bit) install & I never saw any virtualization package, where was it?

It's one of the options when you choose the system components ie. Desktop Environments, Applications, Development, Servers, Base System, VIRTUALISATION, Clustering, Cluster Storage, Languages.

If you didn't see it during the installation process, go to 'Add/Remove Programs' and you should find it there, it'll install a XEN-kernel.

hth

Actually, VMware Server is free and allows you to create your own virtual machines. I've been using it regularly and it works well.

I'll look more carefully next time.

Thanks for the tip. -- I wonder if the fact that I did a KDE install makes a difference? (Should have mentioned that.)

Definitely, thanks again.

That shouldn't matter because it is at the same stage that you choose whether you want gnome or kde
Desktop Environments (KDE or Gnome)
Applications,
Development,
Servers,
Base System,
VIRTUALISATION,
Clustering,
Cluster Storage,
Languages.