tldr/pages/common/ionice.md

ionice

get/set program io scheduling class and priority

• sets process with PID 89 as an idle io process

ionice -c 3 -p 89

• runs 'bash' as a best-effort program with highest priority

ionice -c 2 -n 0 bash

• prints the class and priority of the processes with PID 89

ionice -p 89