ionice

Get or set program I/O scheduling class and priority. Scheduling classes: 1 (realtime), 2 (best-effort), 3 (idle). Priority levels: 0 (the highest) - 7 (the lowest).

Set I/O scheduling class of a running process:

ionice -c {{scheduling_class}} -p {{pid}}

Run a command with custom I/O scheduling class and priority:

ionice -c {{scheduling_class}} -n {{priority}} {{command}}

Print the I/O scheduling class and priority of a running process:

ionice -p {{pid}}