Virtualization

In theory you can virtualize every workload. But you need to remember that all virtualized workloads share the same ressources. This means two things:

1. you should have redundancy (a cluster of virtualization systems) because if one box fails all virtualized workloads will fail too

2. if you virtualize workloads you may run into bottle necks (too less RAM, CPU or IO(network or storage), so all systems loose performance)

But you can use the physical systems better than single systems. I read, that usually a normal server only uses 5-30% of his ressources in normal work. So you can save 2 servers if you virtualize the workloads of 3 systems which are usually only at max 30%.

You also can overprovision, so you can virtually use more performance than the physical system needs.

For instance: You have a K1000 (2 CPU, 4 GB RAM, 500GB hdd) and a K2000 (1 CPU, 4GB RAM, 250GB hdd) but you have only a dual core system with 6 GB RAM and 640GB HDD. If you wouldn't virtualize, you were not able to run both machine except you would buy another system. You can run both workloads on one system without problems as long they don't need all of the granted ressources. If you run into the ressource conflict, you have one of the flaws of virtualization.