The Great Virtualisation Secret

By combining paravirtualisation technology with clustering technology, live migrations can now be done with hardly any noticeable downtime to the user with the additional benefit that if any thing does go wrong with the migration, you have an instant fallback position due to the clustering technology involved.

On a side note….you do of course have all your virtualised servers clustered, don’t you!

Where Can I Get Paravirtualisation?

Now here’s the problem.  Remember the definition on paravirtualisation that:-

Virtualisation technology is built into the operating system and the virtual guest operating systems are aware that they are virtualised.

In other words no emulation or third party software is involved in the virtualisation (on a side note if you do have emulation or third party software then it is known as full virtualisation which can be a bit misleading).

Well currently only two vendors support true paravirtualisation that is of any use - the aforementioned Red Hat with their RHEL OS and Microsoft with their Hyper-V. 

Microsoft only support their latest Windows 2008 Server OS in paravirtualised mode plus SUSE Linux via a downloadable option whereas Red Hat support a number of versions of Linux.  Any other virtual guest OS will be run in fully virtualised environment.

So what about VMWare…well VMware does have a number of benefits but paravirtualisation is not one of them unless you think of VMware as an operating system which has its own set of database and backoffice applications designed specifically to run on VMWare.