iorenice
Display or change I/O priority of existing process. toybox
On Linux
Linux
Display or change I/O priority of existing process. CLASS can be "rt" for realtime, "be" for best effort, "idle" for only when idle, or "none" to leave it alone. PRIORITY can be 0-7 (0 is highest, default 4).
iorenice PID [CLASS] [PRIORITY]