[wellylug] virtualisation options?

[Daniel Pittman]

Peter Lambrechtsen <plambrechtsen at gmail.com> writes:

> I would chose VMware every time.  The ease you can move VM's between a
> Windows/Linux host is just too easy, plus VMServer is free and a very
> solid app.

Given the dependencies and pain of VMWare Server 2 I couldn't recommend
it to anyone, absent the non-free nature of the tool.

> There is XEN or VirtualBox from Sun.  Both are ok, Virtual Box is
> getting a whole lot better for end-user UI

...but still has trouble with accurate CPU emulation, at least in some
versions.  When the Linux kernel started using "long nop" sequences for
various purposes this showed that your choices for accurate CPU
emulation were KVM and VMWare — everything else fell down...

> XEN is extremely fast due to it only being a hypervisor running on
> your existing kernel.

Xen performance with hardware virtualization (eg: any Windows) is
indistinguishable from VMWare, KVM, or any other solution.

That is to say, performance is entirely dependent on the quality of the
paravirtualized drivers you have, for which there are limited free (as
in beer, or as in freedom) options available.

[...]

> Both XEN and Virtualbox need a recompile when you update the kernel,
> however with XEN normally when you do a packaged kernel update it also
> includes all the updates you need.

Eh?  The Xen hypervisor ABI is generally fairly stable, so you shouldn't
need to change that, the dom0 or the domU instances that often.

> But to run XP you would need a CPU that supports virtualsation.  Which
> on a stock laptop may not be able to do it.

*nod*  This is the biggest limitation of getting *good* emulation; on
that basis VMWare is the least awful fallback choice, I would say, if
you can't run KVM.

Regards,
        Daniel