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). More information: https://manned.org/ionice.

• Run a command with the given scheduling class and priority:

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

• Set I/O scheduling [c]lass of a running process with a specific [p]id, [P]gid or [u]id:

ionice -c {{scheduling_class}} -{{p|P|u}} {{id}}

• Run a command with custom I/O scheduling [c]lass and priority:

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

• Ignore failure to set the requested priority:

ionice -t -n {{priority}} -p {{pid}}

• Run the command even in case it was not possible to set the desired priority (this can happen due to insufficient privileges or an old kernel version):

ionice -t -n {{priority}} -p {{pid}}

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

ionice -p {{pid}}