[CentOS-virt] CentOS 8 Install as DOMU in PV Environment

Mon Sep 28 21:04:16 UTC 2020
Christoph <mangel at gmx.de>

AFAIK the support for Xen would not be available in CentOS 8 (Red Hat
has dropped the support).
You can see the differences between the modes here:
https://wiki.xen.org/wiki/Xen_Project_Software_Overview#Guest_Types
PVH seems still to be the fastest one...
You can use the kernel if you add the elrepo kernel repo to the host.
You can find the informations how to do it here:
https://elrepo.org/tiki/kernel-ml
After adding the repo you can install the elrepo kernel like an other
rpm package with "dnf install kernel-ml".
AFAIK this kernel supports all the modes of xen (HVM, PV, PVH etc)

A short howto without details:
1. Start the DomU in HVM mode
2. Install the repo and the kernel-ml pkg
3. Make the kernel-ml as default kernel
4. Reboot the DomU in PVH mode.

The requirement for this is a xen hypervisor install with a grub for xen
what support boot of such a DomU.
The CentOS 8 pkgs from Steven repo ("Xen made easy" project) doesnt have
such a grub bin. I've build it for me here and can share it with you if
you want.

You can of course use CentOS 7 as far as you dont need a newer versions
of the services/applications etc...

A simpler solution is to use Citrix XenServer but not all features are
for free...

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Greetz

Am 27.09.2020 22:23, schrieb 9f9dcad3f78905b03201 at bcirpg.com:
> Christoph,
>
> I understand this is the better option if HVM is available.. Im not
> sure how to make use of this kernel in a non-HVM, PV environment. I'm
> a little disturbed by the fact that there isnt PV support in CentOS 8,
> I hope it comes later so at least PVH becomes an option.
>
> As for using this kernel in a PV only environment, the only route
> would be attempting an in place upgrade and try to install it as part
> of the upgrade. I am not willing to spend the time to do this and will
> use Centos 7 or other operating systems instead.
>
>
> Thanks.
>
>