====== Ionice ======

**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.

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====== Scheduling Classes/Priority Levels ======

Available scheduling classes are:
  * 0 -> none (equivalent to the default of 2)
  * 1 -> real time - first, priority access to the disk, only available to root user
  * 2 -> best effort (default if not specified)
  * 3 -> idle - use cpu only when no other process has asked for cpu time

Priority Levels:
  * 0-7
    * 0 -> Highest priority
    * 7 -> Lowest priority

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====== Get Process I/O Info ======

Example of Getting the i/o scheduling class and priority of a process with PID 1637
<code bash>
> $ ionice -p 1637                                                                                                                                          
none: prio 0
</code>

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====== Set Class/Priority ======

Remove a large file, using only idle cpu time
<code bash>
ionice -c 3 rm /var/log/mylargelog
</code>

\\
Remove a large file, use best effort scheduling, with a low priority
<code bash>
ionice -n 7 rm /var/log/mylargelog
</code>

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