vsched is used to schedule both parallel and serial work, to all of the various node types.

• Each running job has exclusive access to the nodes assigned. Once your job is running and you are assigned a node or several nodes, you have exclusive access to them. There is no sharing; you have 100% of the nodes you've acquired.

• Scheduling is first-in, first-out, with backfilling. The first-in-first-out part is self-explanatory. To see an explanation of backfilling, click on the link.