Re: [ovirt-users] Use an oVirt-VM as a VDSM server
On Monday, April 30, 2018 9:02:35 AM EDT James Michels wrote:
Greetings.
In terms of teaching our students how to create and configure an oVirt
infrastructure, we're planning to provide each of them a VM that will act
as a Manager server, which has no issues so far. The problem is that we
don't have enough physical machines to use as virtualization servers
(VDSM), therefore we have been trying to use a CentOS7 based oVirt guest to
run as a VDSM server.
However, when trying to add it as a host, a (logical) error message shows
up saying that the VM doesn't allow virtualization.
The question is simple: Is there a way to enable virtualization on an oVirt
VM, so we can deploy them as VDSM servers?
This is oVirt 4.2.2 FWIW.
Thanks
James
James,
Yes its possible, when you install (or re-install) a PHYSICAL host, in the
host popup dialog there is a kernel tab. Enable 'Nested Virtualization' kernel
parameter. Once that is enabled and the host is rebooted then you can use VMs
as VDSM hosts for your setup.
Some gotchas:
- Make sure your cluster cpu type actually matches your physical hosts, if you
select a wrong one then the exposed CPU options will be wrong and the nested
virtualization will not work properly.
- You will need to enable mac spoofing for the networking to work correctly.
- VMs running inside a host that is a VM itself will likely have a fairly
significant performance hit due to the nested virtualization.