[CentOS-virt] new to xen - got questions, please

Wed Jun 16 17:54:07 UTC 2010
Ed Heron <Ed at Heron-ent.com>

On Wed, 2010-06-16 at 12:11 -0400, Steve Campbell wrote:
> I just installed Centos 5.5 with the xen kernel on an older machine. It 
> has Xeon processors and a 700 Mhz processor speed, so I realize I must 
> use para-virtualized guests. Reading the Centos/RH Virtualization Guide 
> gives examples of the process of installing guest hosts, but it only 
> lists installing Windows as a fully-virtualized host.
> 
> Is that because they only showed those types of examples or is it that 
> Windows hosts can't be para-virtualized?

  I'm not sure how far the para-virtualized drivers for MS Windows (XP?)
have gotten.  I would only install a MS Windows XP virtual machine as a
fully virtualized guest, at this time.  I haven't begun to work with
Vista or 7.

  If I were restricted to the older machine, I'd explore using VMWare.
The bare metal version should be comparable to XEN performance, but the
free version is restricted as far as the number (3?) of virtual machines
that can be run.  It'll virtualize MS Windows guests on older hardware.

  Evaluate why you are using virtual machines...  If this is an
evaluation period, the older equipment is OK; Explore the alternatives.
If this is a production machine, you'll be happier with a newer
computer.

> Secondly, what's the normal what to install a Centos guest when it comes 
> to defining the installation media (it lists HTTP, FTP, or NFS). This 
> machine only has a CD drive, so I'm a little confused about the best way 
> to handle this since the Centos installation now consists of 6 CDs. A 
> brief explanation would be handy.

  Download the DVD and put it in /var/lib/xen/images/, set it as a
virtual optical drive.  The process is slightly different depending on
whether you are creating the virtual machine using a xen config file,
virt-install (command line) or virt-manager (gui).