Hi all,
We are happy oVirt users for some years now (we started with 3.6, now on 4.2) and we manage most of our virtualization stacks with it. To provision and manage our machines, we use the foreman (for bare metal and virtual machines) on top of it. I made some little contributions to the foreman and other underlying stuff to have a deeper integration with oVirt, like to be able to select instance type directly from foreman interface/api and we rely on it. We use instance types to standardize our vms by defining system resources (memory, cpu and cpu topology) console type, boot options. On top of that we plan to use templates to apply OS (CentOS 7 and CentOS 6 actually). Having resources definitions separated from OS installation help us to keep instance types and templates lists small and don't bother users about some technical underlying stuff. As we are interested in automating oVirt maintenance tasks and configuration with ansible, I asked at FOSDEM oVirt booth if there is any ansible module to manage instance types in Ovirt as I didn't find it in ovirt ansible infra repo. The person to whom I asked the question said that you are planning to remove instance types from ovirt, and this make me sad :(. So here I am to ask why do you plan to remove instance types from oVirt. As far as I know, it's fairly common to have "instance types" / "flavors" / "sizes" on one side and then templates (bare OS, preinstalled appliances...) on other side and pick one of each to make an instance. If this first part is missing in future version of ovirt, it will be a pain point for us. So, my question is, do you really plan to remove instances type definitely ?
I don't know the future plans (maybe someone else can comment), but I have heard that instance types are barely used. You might be the first person I know of who is using them.
The argument for keeping templates but removing instance types is probably that templates already are effectively instance types. That's why I never use them. For example, create a CentOS template with 16 CPUs, 32GB RAM, 500GB disk ... that's effectively a large instance type. Create another template with 1 CPU, 2GB RAM, 30GB disk ... that's effectively a small instance type.
Is there a use case beyond this that instance types provide that templates don’t?
