I'm installing 6.11.5 as my 6.9 cannot be migrated for some seeming pulp2/3 issue. That's another challenging topic I don't have the tears for today.
I have a script I've been using, since the scheduling in Satellite/Foreman seems to choke itself. It uses hammer, xargs, parallel and is called by cron. Quite simply, it moderates the flow of hammer repository synch runs so that only a few (one per core) get into the scheduler and it gatekeeps the rest until space opens up. As we have a sizeable number of repos for the machines I inherited, this keeps the machine running and the repos synching successfull