virtualisation technology

MLUG – 29th August, 2008

Virtualisation Technology

• Term commonly used for many years• Abstraction of hardware resources

– Partial Virtualisation– Full Virtualisation– Operating System-level Virtualisation– Application Virtualisation (Emulation)

Virtualisation

• Partial simulation of hosted hardware• Not the same idea behind modern

virtualisation• Limitations of running software on

partial virtualisation led to Full Virtualisation

Partial Virtualisation

• Implemented in 1967 - IBM CP40(VM family)

• Complete simulation of host hardware– Indistinguishable from host capabilities

• Originally for distributed terminal-style computing

Full Virtualisation

• Full virtualisation on x86 platform in 05/06

• All current “standard” virtualisation platforms are examples of Full Virtualisation– Some vendors such as VMware claimed full

virtualisation prior to this, but technically incorrect

• Virtual machines by definition are unallowed to “pierce the virtual machine”

Full Virtualisation

• “Containers”• Often used in Virtual Hosting

environments• Very low overhead• Examples of OS-level Virtualisation are

– Chroot (basically)– OpenVZ– Parallels Virtuozzo– FreeBSD Jail

OS-level Virtualisation

• I know that you know what this is• Engines designed to execute

applications on platform (instruction set) that it was designed on

• Play your Super Nintendo games on your PC

Emulation

• Examples– Parallels Desktop for Mac– Parallels Workstation– VMware Fusion– VMware Player/Workstation

Desktop Virtualisation

• Examples (OS-level Virtualisation)– OpenVZ– Virtuozzo– Jail– Linux V-Server

• Examples (Full Virtualisation)– VMware GSX (old)– VMware Server (v2 RC2 is latest version)

• This is what I will demonstrate

Server Virtualisation

• VMware ESX– Pretty much the standard– Very low overhead optimised host O/S– Hardware requirements are strict– Found in large corporate facilities

Enterprise Virtualisation