On Fri, 2006-02-24 at 09:20 -0500, Brad Smith wrote:
I guess my question could be rephrased: If xen comes with Fedora is
there a reason for someone who wants to run virtual test systems in
Fedora to use anything else?
Xen is a para-virtualisation system - the virtualised system/os needs to
built in a way that is appropriate for virtualising. This means that
you are (currently) unable to use xen for running windows images or even
installing older (non xen aware) versions of Linux. Since Xen requires
support at kernel level it really needs to be in core if its supported
(and it is both in core and supported).
Qemu is a more complete or maybe more traditional virtualisation setup -
it effectively emulates the hardware of a standard system. However its
rather slower than Xen. You can also emulate an entirely different
architecture under qemu (I have installed a x86_64 fedora on a i386
under qemu - but it was glacially slow). There is a non-free kernel
module that speeds up emulation of i386 on i386. Qemu can also be used
to run binaries for one system on another without emulating the complete
system - in a way vaguely analogous to what wine does.
VMware is effectively a commercial, shinier, faster version of qemu
(VMware would dispute this - they were there way before qemu). Its much
easier to manage and probably better on some cases where the qemu
emulated hardware is insufficient. Its obviously not a candidate for
Fedora even in its new free (gratis) form. There is also a big brother
- ESX - which runs virtual machines over an ESX kernel running on bare
metal, which is used for virtualising services. I don't think VMware
does anything other than i386 running on i386 (unlike qemu).
Qemu would be a good extras candidate. I'm a bit surprised to see its
not in extras at present.
[ Nigel Metheringham Nigel.Metheringham(a)InTechnology.co.uk ]
[ - Comments in this message are my own and not ITO opinion/policy - ]