First off, i’d like to just get the site kicked off with a brief +/- i wrote a few weeks ago on Para-virtualization.

http://img440.imageshack.us/img440/8415/800pxviridianarchitecturl4.png

+ Paravirtualization (PV) provides major security benefits, as the host server generally cannot access the virtual machines inside (if compromised) unlike Full Virtualization (FV). Also, virtual machines are totally black-boxed, and cannot see other VM’s on the same server.

+ PV provides an infrastructure with a lot more redundancy, backup and fail-over options than FV; using proprietary technologies such as “VMotion” (VMWare) which allow a virtual machine to be ran across 2 separate physical hosts in 2 separate locations.

– PV is expensive to run; as you will need hardware that is officially supported to run the hardware on (generally), compared to FV, such as VMWare Server, which you can install on any hardware running a supported Operating system such as Ubuntu, Win. XP, etc.

http://blogs.vmware.com/vmtn/images/2007/11/15/multimode.png

– Most common variant of Virtualization used in the Enterprise today.
– Examples include VMWare ESX/Vi3, XenSource aka Citrix.
– Uses a “Hypervisor” or Virtual Machine Monitor, to allow multiple OS to run on a host computer simultaneously. VMWare uses vmkernel as its Hypervisor.

Tomorrow –  Hypervisor types.