Hi Michal,

many thanks for the prompt answer. That explains our sightings were we were not able to deploy an instance with more vRAM than we had physically left.

Cheers,

Oliver

Hi Oliver,

Here’s a link to the template we’re using - https://opendev.org/openstack/kolla-ansible/src/commit/e628cbddb19fa26de7a5f1d1b0027c0bc70dab38/ansible/roles/nova-cell/templates/nova.conf.j2#L15

As you can see we’re setting ram_allocation_ratio to 1.0 by default, but we do not set cpu or disk allocation ratios - so the defaults there come from Nova itself.

Check (and change 2024.2 to your OpenStack release):

- https://docs.openstack.org/nova/2024.2/configuration/config.html#DEFAULT.initial_cpu_allocation_ratio

- https://docs.openstack.org/nova/2024.2/configuration/config.html#DEFAULT.cpu_allocation_ratio

- https://docs.openstack.org/nova/2024.2/configuration/config.html#DEFAULT.initial_disk_allocation_ratio

- https://docs.openstack.org/nova/2024.2/configuration/config.html#DEFAULT.disk_allocation_ratio

Hope that helps,

Michal

On 12 Dec 2024, at 10:34, Oliver Weinmann <oliver.weinmann@me.com> wrote:

Hi all,

what are the default values for:

cpu_allocation_ratio

ram_allocation_ratio

disk_allocation_ratio

when using kolla-ansible?

I can't seem to find any clear statement about it.

Currently I assume they are 1.0 for each.

Cheers,

Oliver