How is Xen different?

• Traditional Virtualization solutions (VMware, Virtual PC) fully virtualize the x86 architecture

• The x86 architecture is hard to virtualize.

  • Fully virtualization comes at a high price

• Xen uses para-virtualization

  • Guest OS must avoid hard-to-virtualize features of the x86
  • Requires modification of Guest OS
  • Results in significant reduction in virtualization overhead
  • Linux involved about 3000 lines of code modifications

Notes: