Setting Kibana logging levels controls how much startup, plugin, and request detail the server records during troubleshooting. Raising the root level temporarily exposes lower-level messages when the UI is slow to come up, a plugin fails to initialize, or the connection to Elasticsearch needs closer inspection.
Kibana reads logging settings from kibana.yml at startup. logging.root.level sets the default threshold for loggers that do not have a more specific override, defaults to info, and accepts off, fatal, error, warn, info, debug, trace, and all.
The package-based Linux layout keeps the active configuration at /etc/kibana/kibana.yml and applies changes through systemctl. Package logs are commonly read from /var/log/kibana/kibana.log or the systemd journal, while Docker uses docker logs and archive installs use $KIBANA_HOME/logs. Kibana validates logging settings during startup, so an unsupported level or broken YAML can keep the service from starting.
$ sudo cp -a /etc/kibana/kibana.yml /etc/kibana/kibana.yml.bak
$ sudoedit /etc/kibana/kibana.yml
Archive and container installs usually keep kibana.yml under /usr/share/kibana/config instead of /etc/kibana.
logging.root.level: debug
Use debug for short troubleshooting windows before moving to trace or all. Higher levels can expose request details and generate enough log volume to fill small disks quickly.
Tool: YAML Validator
$ sudo systemctl restart kibana.service
$ systemctl is-active kibana.service active
$ sudo grep -F "[DEBUG]" /var/log/kibana/kibana.log [2026-06-18T13:58:36.169+00:00][DEBUG][cli] Kibana configurations evaluated in this order: /etc/kibana/kibana.yml [2026-06-18T13:58:36.170+00:00][DEBUG][config] Marking config path as handled: elasticsearch [2026-06-18T13:58:36.171+00:00][DEBUG][config] Marking config path as handled: logging [2026-06-18T13:58:39.940+00:00][DEBUG][root] prebooting root [2026-06-18T13:58:40.108+00:00][DEBUG][plugins-system] Setting up plugin licensing ##### snipped #####
If your deployment sends Kibana output to the systemd journal instead of /var/log/kibana/kibana.log, run sudo journalctl -u kibana.service -b -p debug and confirm the same [DEBUG] entries appear.
logging.root.level: info
info is the default root level and keeps routine operational logs without leaving debug or trace detail enabled.
$ sudo systemctl restart kibana.service