Pacemaker creates a unit override for systemd resources when starting them, and removes the override when stopping them. It has to reload systemd to make it take effect.

If there are multiple systemd resources starting or stopping in the same transition, systemd has to be reloaded for each one, which can add significant delays unnecessarily.

It would be nice if we could create or remove all the overrides needed in a transition at once, and reload once, at the start of the transition. That will be difficult with the current model since each start and stop is handled individually by the executor, which has no knowledge of the transition.