Skill 3 in course 2.2: Operating System

Processes, Tuning and Logs

Find and control processes, change their priority, apply tuning profiles, and read and keep the system's logs.

Intermediate3 lessons15 exercises2 h 5 min
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You will be able to

  • Identify the processes that use the most CPU and memory, and stop them with the right signal.
  • Start a process at a chosen priority and change the priority of a running one.
  • Choose, apply and verify a tuned profile, including the recommended one.
  • Query the journal precisely, and make it survive a reboot.

Lessons

  1. 01Finding and stopping processesRead the process list, find what is eating CPU or memory, and stop it with the gentlest signal that works.pstoppgreppkillkillkillall0/5 exercises
  2. 02Process priority and tuned profilesGive important work more CPU with nice and renice, and apply a tuned profile that fits what the system does.nicereniceps -o nituned-admtuned-adm listtuned-adm recommend0/5 exercises
  3. 03Reading logs and keeping the journalQuery the systemd journal by unit, time, priority and boot, write your own entries, and make the journal persistent across reboots.journalctljournalctl -ujournalctl -pjournalctl -bjournalctl --sincelogger0/5 exercises