Virtualization
Summary
Hypervisors
Operating System of Operating Systems = Hypervisor (or VMM)
Two Types:
- Native/Baremetal
- Hypervisor is running on hardware
- Hosted
- Hypervisor runs on top of host OS
- VMWare Workstation
- VirtualBox
Native Hypervisors offer best performance
Connecting the Dots
- IBM VM 370 (70’s)
- Microkernels (late 80’s & 90’s)
- Extensibility of OS (90’s)
- SimOS (90’s)
- Xen & VMWare (early 2000’s)
Full Virtualization
Leave guest OS untouched
- Even though guest OS doesn’t have the same level of privilege that it’s
expecting
- Privilege escalation attempts are trapped in hypervisor, which emulates intended functionality
Para Virtualization
Modify source code to make it away that it is a guest
As far as applications are concerned, nothing is changed because the upper interfaces are left intact
Only less than 2% of code needs to be changed
- Proved by Xen