- Modern computer systems are composed of various hardware and software layers
- Virtualization inserts a software layer (VMM) at different points in this architecture, comes in three variants:
hardware-level virtualization
operating system-level
Application level
Hardware Level Virtualization
- Virtualization layer sits right on top of the real hardware
- Since the VM presents a version the real machine, all software written for that hardware (x86) will run on that virtual machin
- Original design from IBM in the 1960’s
Operating System Level Virtualization
- Virtualization layer sit between the operating system and the application programs that run on the operating system
- Virtual Machine runs applications, or sets of applications written for the operating system but in a controlled environment
(Layers order shown below)
Application
Virtual Machine
VMM Applications
OS
Real Mchines
Application level virtualization
- The virtualization layer sits as an application program on top of the operating system
- Can run any programs written for that virtual machine abstraction regardless of the operating system hosting that virtual machine
(layers order shown bellow)
Java Byte Code
JVM
APPLICATIONS
OS
Real Machine
