Greetings @sak,
A couple things to consider…
Take a look at this discussion: Allowing to schedule node maintenance with a possibility to run new jobs until the maintenance begins
It led to this design document: https://pbspro.atlassian.net/wiki/spaces/PD/pages/879493121/Node+maintenance+window+enhancement
And ultimately led to the introduction of maintenance reservations, thanks to @vchlum.
In terms of running yum as root, I suggest you update your sudo configuration so that one of your user accounts may run “yum update” on your nodes. The update itself may be run from within a job. Since the node will reboot, you won’t want the job to be rerun-able.
Thanks,
Mike