Virtualization Concepts - Paiet/Tech-Journal-for-Everything GitHub Wiki

Introduction to Virtual Machines

  • 0.1 Virtualization Concepts (Week 1)

    • What is a Virtualized Environment?
      • A software representation of the physical hardware environment.
    • What is a Hypervisor?
      • Software that helps to Manage Virtual Machines
      • translates and controls between hardware and VMs.
    • What is a VM?
      • A virtual machine
    • What is a Host or Guest?
      • Host: Underlying Physical Machine with an Operating System.
      • Guest: A virtualized machine that runs on top of the host.
    • What is hardware assisted virtualization?
      • e.g. Intel VT or AMD-V
      • e.g. CPU instructions in a VM
        • Sent to emulated CPU by hypervisor.
        • Hypervisor then translates these to the physical CPU (High Overhead)
        • Virtualization Extensions essentially map the Physical CPU to the virtual CPU, essentially sending any instructions directly to the real CPU.
        • http://ark.intel.com/VTList.aspx

  • 0.2 Virtualization Benefits and Limitations (Week 2)

    • Business & Personal
      • Usage Benefits
        • Legacy software support -- Consolidation
        • Training/QA -- Consolidation
        • Activity Portioning -- Isolation (Containment)
        • Administration -- Consolidation, Isolation, Migration
        • Failover Infrastructure - Migration
        • Costs - High Optimization
      • Usage Limitations
        • Consolidation Ratio
        • Can be challenging
          • Hardware & Hardware Configuration
            • more RAM, Storage, Networking
            • Costs
          • Administration & Configuration
            • can be Time
            • can be Technology
    • Security
      • isolation
      • all involved
        • guests
        • hosts
        • networking

  • 0.3 Virtualization Technologies (Week 3)

    • Type I
      • "Bare Metal" Hypervisor
      • Hypervisor that runs on top of host hardware
      • simple diagram
      • e.g. Microsoft Hyper-V, VMWare ESX
    • Type II
      • Hypervisor that runs on top of host OS
      • simple diagram
      • e.g. Oracle VirtualBox, VMWare Workstation
    • How do we get started?
      • Hardware must support the following
        1. 64-bitMulti-core CPUs.
        2. IntelVT or AMD-V CPU virtualization extensions.
        3. NoeXecute(NX)/eXecuteDisable(XD).
        4. Full BIOS support for hardware virtualization.
      • Guest OS with license
      • Possibly Host OS with license