Virtualization

Virtualization

1. Hypervisor

   • creates and run virtual machines
   • Host/guest machines
   • Type 1
     • Hypervisor on bare metal
   • Type 2
     • Hypervisor on top of OS
   • Proprietary
     • MS Hyper-V
     • VMware ESX/ESXi
   • Open source
     • Citrix XenServer
     • KVM

2. Virtual Machine

   • Virtual Disks
     • file on the physical drive
     • fixed
       • thick disk (VMware)
     • dynamically expanding
       • thin disk (VMware)
   • Virtual NICs
     • software
   • Virtual Switches
   • Memory
     • inital size, then on the fly as needed
     • static
   • Storage Virtualization
     • usually SAN
     • N_port ID virtualization (NPIV)
       • multiple host computers share a single physical fibre channel port identification, single host bus adapter to register mulitple World Widw Names WWNs and N_port identification numbers
   • Guest Tools
     • help guest-host interation

3. Migration

   • P2V
     • Manual
       • manually create VM copy from OS over
     • Semi-automated
       • SW tool helps
     • Full automated
       • SW w/o admin assistance
     • online/offline
       • offline more reliable online remains running during migration
   • V2V
     • copy/restore
     • convert
       • open virtualization format (OVF)
   • V2P
     • e.g. no app support on virtual or test how app performs on physical
     • rarely, complex
     • Symantec Ghost

4. Virtual Machine Cloning

   • copy e,g, quickly create a dev env