Managing Networking and Templates without Pooling

creoleMalady

I have a rack of servers that are all recycled hardware running XCP-NG managed with Xen Orchestra. CPU's often don't match between hosts, so managing them as one pool is a "no-no" based on documentation.

The network is a mess partly because each host has been managed as a separate pool with its own templates and network configurations.

I want to be able to configure templates and networks across them in a common place. Each pool has diverged over time and I have managed them poorly, which has led to annoyances and mistakes.

Any suggestions on how I could generate and store templates in a common place (I like being able to create templates with cloud-init) and be able to trunk VLAN's and networks across all hosts without having to configure them independently.

olivierlambert

The most straightforward way is to use... pools. That's exactly how/why it's designed like this.

Outside that, this would require to use an extra layer on top to manage "cross pool" templates.

planedrop

Is it that the CPUs don't match generation wise or don't match vendor wise? If same vendor normally it should be OK even if different generations. Sure it's not "ideal" but usually from what I know should be OK.

But other than that there is no way to do this right now. Normally things like network setup should be a fairly rare thing to change, so just doing it in a few places when that's needed is probably the best approach.

tjkreidl

@planedrop CPU compatibility is automatic now, albeit the CPUs have to be somewhat similar. That said, Intel and AMD CPUs cannot be mixed. There used to be scripts out there that you could use to check compatibility but I have not seen them for quite some time. Note that the CPU mask will be reduced to the lowest common denominator -- that is to say, the oldest, least-featured CPU in the pool -- so I would be careful what servers you include in your pool(s).
See also: https://xcp-ng.org/forum/topic/6896/non-server-cpu-compatibility-ryzen-and-intel/21

planedrop

@tjkreidl Oh yeah for sure, I was saying you don't want to mix vendors but mixing cross gen can be OK depending on various factors.

But I'd still say it's best for people to go with same gen chips if possible.

Either way though managing a few different pools isn't too challenging IMO so I think that is what OP should do, just manually managed them.

dredknight

@creoleMalady one more suggestion for the sake of an alternative solution. If you insist on managing multiple servers not in host (even though running them in a pool would equalize the CPU features to the oldest CPU available) you can use Cloudstack as a management platform to do the templates and networking for you. It dynamically transfers templates and assigns networks on demand on the hosts as you provision vms on them.

The disadvantage is that you need to learn Cloudstack which can be much of an overhead by its own if you dont want to go too deep.