Virtualization

Virtualization: the process of using software known as the hypervisor to allocate hardware for more efficient usage of the operating system

• Virtualization can allow multiple operating systems to run concurrently on one physical machine and to deploy multiple virtual images.

  • Why? Imagine developing a program, and you want the program to work on multiple operating systems. To develop the program, you purchase three devices with each operating system or virtualize the operating system on a computing device.

• Two types of Hypervisors:

  • Type 1 (Bare-metal hypervisor): a layer of software installed directly on top of a physical server and its underlying hardware

    • Exists directly on the hardware

    • Typically reserved for servers (clouds)

    • No pre-existing operating system, so 100% of hardware resources can be given to virtual machines (VMs)

  • Type 2 (Hosted hypervisor): sits on an existing OS that relies on the host machine’s pre-existing operating systems to manage calls to CPU, memory, storage, and network resources

    • Typical set-up for workstations OR end user devices

    • Slower for type 1

    • Host OS: portion of CPU and ram resources to guest OS

    • Guest OS: virtualization to new operating systems