[CentOS-virt] CentOS 6 VM image for paravirtualizaton on CentOS Xen server

Mon Mar 16 00:11:48 UTC 2015
Peter <peter at pajamian.dhs.org>

On 03/16/2015 11:25 AM, Nico Kadel-Garcia wrote:
> I've got CentOS VM's running fine, and have done them before. But
> previously, I deployed the same base OS on the VM as on the Xen
> server, so paravirtualization posed few risks. And I had control of
> the DHCP setup. so I could trivially set up a tftp server to do a
> non-CD installation, because Xen, at last look, doesn't support
> installing a paravirtualized host from a CD image.

It does as long as (1) the kernel has Xen PV support (CentOS 6 standard
kernel does) and (2) it has the necessary drivers in the initrd (I think
this is where the CD image is lacking), then you should, in theory, be
able to pv-grub boot to the CD.  Alternatively you can boot to the CD on
another box first, copy the kernel off to a USB stick, and generate a
new initrd with the xen drivers included, then put those on the Xen host
and boot to the VM CD image using those in the kernel= and initrd= lines
in the domain.cfg file.

The other way is to boot to the CD as an HVM domain and install, then
convert it to a PV domain afterwards, which is not all that difficult to do.

There is a third way which involves using yum to install the @core group
plus kernel to an image, then tweak and boot to that as a PV domain.
This is how I have done it in the past.

> So I'm right back to my effectively unanswered original questions. So
> please: I asked a very specific pair of questions, and they remain
> unanswered. CentOS 5 Xen server (hypervisor, or Dom0, whatever we want
> to call it this week): Does CentOS 6 work, paravirtualized, on such a
> server?

Yes, I have done that until I upgraded the CentOS 5 host to CentOS 6 a
couple years ago.

> And given my deployment issues, does anyone have a base OS
> image I can get a copy of?

Sorry my image templates that I use are highly customized for my own
work, but I have told you three different ways to accomplish it above.