Re: serious virtualization without HW support?

[Tom Horsley <tom horsley att net>]

On Wed, 1 Apr 2009 08:39:36 -0400 (EDT)
Robert P. J. Day wrote:

> and it occurs to me to ask whether anyone would want to get
> *seriously* into virtualization without having machines with those
> extensions.

Depends - the Xen style paravirt stuff works well (for some definition
of "well") without hardware support.

>   is it safe to say that, by now, most modern systems come with VT or
> AMD-V support?  and by "serious" virtualization, i don't mean someone
> downloading and goofing around with it, i mean people who want to set
> up virtual corporate servers or mission-critical stuff.

My current experience with using virtual machines for testing tools
such as debuggers that interact with the system at a low level leads
me to suspect that mission-critical stuff should stay as far away
as possible from virtual servers :-).

If I look at summaries of test failures, there are some tests which
consistently fail on virtual machines, yet never fail on real hardware.
I have very deep suspicions about virtual machine reliability.