Lesson 3 · Provisioning

Manage Virtualization

Server virtualization sits at the core of IaaS. Before anything else gets provisioned, something has to decide how physical hardware gets carved up into virtual machines — that's the hypervisor's job.

3.2

Manage Virtualization

Server virtualization is the primary element of IaaS solutions. Traditional virtualization — as opposed to containerization — starts with the hypervisor: a management layer sitting between the physical server hardware and the VMs configured on it. There are two hypervisor designs, and the difference between them comes down to one question: does it run independently of an operating system?

3.2a

Oversubscription

One unique aspect of virtualization: administrators can allocate more resources to VMs than the host actually has. It works as long as not every VM demands its maximum at the same moment — higher density, better utilization, with a real ceiling underneath it.

Host RAM installed 64 GB

Number of VMs 10 VMs

RAM assigned per VM 8 GB

Typical concurrent usage per VM 40%

Host capacity

INFO — Virtualization configuration and optimization is covered in-depth in a later module.

§ 3.2 · Manage Virtualization