The Great Virtualisation Secret

This all sounds very technical but it essentially means that you are no longer locked into the resources that you would have had to allocate via software virtualisation.

Say for example you had 4GB of physical memory and allocated 2GB to VM1 and 2GB to VM2.  

At night VM1 might no longer require as much memory due to less people using that virtual server. 

This memory could then be dynamically allocated/requested by VM2 should you decide to run extra processes on VM2 at this time such as a network back up.

Live Migration

Live migration doesn’t seem like a major benefit to a corporation unless you understand that what we’re talking about is upgrading and moving critical physical and virtual servers to better hardware without any downtime.

In fact it’s actually between 45-300ms downtime depending on how complicated the actual migration is.

Again live migration is nothing new but the speed of the live migration gained by paravirtualisation is!

In fact, one of the negatives about classic virtualisation was how to upgrade the hardware of a server or set of servers required for 24x7 operation.

The traditional answer was that you would run off of a standby system whilst taking the virtual server down and copying its image files to the newer physical server.

This copying process could have involved at least an hour or more of downtime depending on the size of virtualised image files.