I'd like a more systematic way for prioritizing my tasks with nice(1).

Obviously 0 is "normal", 19 is "lowest priority" and -19 is "highest priority", but what about all the other numbers?

If I have a job that is non-interactive (I'll go get coffee while it runs), I'd like to lower the priority a bit, but to which number? Should it be 1 or 2 or 10 or what?

Are there any "well-known" things that each priority number is used for?

The same questions apply to ionice.

1 Answer 1


nice priority numbers only matter in relation to other processes. It's up to you to determine the structure you want and how much granularity you need. You can think of it as 3 for very low granularity or 5 groups for better granularity instead of the full range, e.g., High, Medium, Normal, Low, Really Low, and give those an arbitrary number value, say -19, -10, 0, 10, 19.

The numbers in between can be used as needed when you have the one process that's a little more important than Medium Process X, but not as important as High Process Y. Chances are you won't need them, though.

  • I was hoping there were already some concrete values for X and Y. For example, are there any processes in the Debian distribution that use a nice value of 5?
    – bukzor
    Apr 25, 2012 at 21:28
  • I don't know if there is any consistency from distro to distro what nice levels are applied to what by default. This is something you can check with ps with a command like ps -eo pid,state,nice,args. I cannot locate any documentation that references some sort of standard for these chosen levels.
    – brent
    Apr 26, 2012 at 14:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.