General Information
ionice - set or get process I/O scheduling class and priority
ionice can be used in combination with rm to remove very large files and not impact other, more high priority processes.
Available scheduling classes are:
Priority Levels:
Example of Getting the i/o scheduling class and priority of a process with PID 1637
> $ ionice -p 1637 none: prio 0
Remove a large file, using only idle cpu time
ionice -c 3 rm /var/log/mylargelog
Remove a large file, use best effort scheduling, with a low priority
ionice -n 7 rm /var/log/mylargelog