[CentOS] KVM in CentOS 5?

Thu Aug 7 22:13:04 UTC 2014
Valeri Galtsev <galtsev at kicp.uchicago.edu>

On Thu, August 7, 2014 5:00 pm, Les Mikesell wrote:
> On Thu, Aug 7, 2014 at 4:36 PM, Marko Vojinovic <vvmarko at gmail.com> wrote:
>> >> > On Thu, 7 Aug 2014 22:54:40 +0300
>>> > Eero Volotinen <eero.volotinen at iki.fi> wrote:
>>> > > 2014-08-07 22:49 GMT+03:00 Marko Vojinovic <vvmarko at gmail.com>:
>>> > So, is there any possibility to have kvm on C5?
>>> >
>>>
>>> yes, just do 'yum install kvm' and remember that x86_64 cpu with
>>> hardware virtualization is needed ..
>>
>> ... And in addition to that, I need to have a 64-bit OS running on it,
>> which I apparently don't. Just my luck. :-(
>>
>
> Technically you don't need to have a 64-bit host OS to virtualize a
> 64-bit guest but that may be the way kvm is built.   I know I used to
> run 64-bit linux versions under vmware player on a laptop running
> 32-bit windows XP.    Maybe virtualbox would work...

To the best of my knowledge, vmware emulates generic CPU, therefore, guest
can have different architecture from host. Emulates meaning, in
particular, what is CPU register for guest is actually sitting in RAM.
Therefore, regisetr-to-register operation for vmware guest ias asctually
physical RAM to physical RAM operation which is a couple of orders on
magnitude slower (well, was long ago, and I'm sure still is). And the same
goes about other kinds of CPU command execution of guest OS. This, however
is not the case with KVM, portions of guest machine code is run directly
in physical CPU, in different privilege ring, of course. (more
knowledgeable people will add/correct here).

Thanks.
Valeri

>
> --
>     Les Mikesell
>       lesmikesell at gmail.com
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>


++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
++++++++++++++++++++++++++++++++++++++++