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nice

Processes and system

Usage

nice -n <19..-20> <command>

Starts a command with a lower CPU priority; the value runs from 19 (most yielding) to -20 (greediest), negative values need root, and it affects only CPU, not disk (that is ionice).

Common flags

FlagMeaning
-n 19Lowest priority: yields the CPU to everything else.
-n 10What you get if you run nice with no -n at all.
-n -5Higher priority than normal. Negative values need root.

Examples

nice -n 19 tar -czf backup.tar.gz /data

Compress a big directory without slowing down the rest of the machine.

sudo nice -n -5 ./latency-sensitive

Give a process more CPU priority than normal.

What is running and what is eating the machine. Identifying it comes before killing it.

How to read this

  • Square brackets [ ] mark a part you may leave out.
  • An ellipsis … means you can list more than one.
  • Flags are case-sensitive — in some commands -r and -R do different things.

Questions

Q. What does nice do?

Starts a command with a lower CPU priority; the value runs from 19 (most yielding) to -20 (greediest), negative values need root, and it affects only CPU, not disk (that is ionice).

Q. How do I type it?

nice -n <19..-20> <command> — square brackets mark the parts you can leave out.

Q. How many flags are worth knowing?

3 are listed here; the full set is in man nice. This command sits under Processes and system.

Related commands

man page: man nice