[Users] Adding Nodes after ovirt-engine re-install

Hi, I was wondering if it's possible to add existing ovirt nodes (HVs) to a new installed ovirt-engine ? E.g. the old engine died and there was no backup of it - how would you add the existing HVs without destroying what's already running ? If the above is not possible, is there a "backup guide" you can refer me to ? Ideally though, it should really be possible to "import" existing HVs into a newly setup ovirt-engine. Alex