[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-users] differences between Para-Virtualization and Full-Virtualization?

  • To: Songtao Liu <songtao.liu@xxxxxxxx>
  • From: Nico Kadel-Garcia <nkadel@xxxxxxxxx>
  • Date: Fri, 20 Jul 2007 09:44:33 +0100
  • Cc: xen-users@xxxxxxxxxxxxxxxxxxx
  • Delivery-date: Fri, 20 Jul 2007 01:38:07 -0700
  • Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=XIk41R+ZVjuUl0Zp777NXzVt3dfxXxq5Y/5wFfU/oqy8omZEm3qQgFxnxv9kB155ctoZb6rOfdmoycAoCsl6ul4v+yXOg5TZTqOZH5Sos6ExD6P/BD1BGIuzh4rADZsbZlgaLBHud7qoV/Eel5C4BnXyXjQbnG0lHsCXrWLUErA=
  • List-id: Xen user discussion <xen-users.lists.xensource.com>

Songtao Liu wrote:

Could someone explain me the following questions:

Where are differences between Para-Virtualization and Full-Virtualization in 
the aspects of memory management, CPU and Device I/O, Network?

How is the performance difference between them?

There are dozens of good documents on this. Boiled down to a few lines, full virtualization emulates the entire hardware platform of a guest computer. That can be effective for running an otherwise incompatible operating sytem, like Windows on a Linux server.

Para-virtualization uses a customized kernel, compatible with the host's kernel and "hypervisor", that speaks compatibly and much more directly to your host's hardware. It's much lighter weight, allows memory to be re-allocated among guest domains so a server can run far more guest domains,, and provides a really noticeable to any guest operation that has to talk to the disk. But it requires a compatible kernel on the guest OS, compatible with the Xen version of the host OS.

Xen-users mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.