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references Linux System systemctl / journalctl

systemctl / journalctl

Services beheren en logs lezen met systemd.

Services beheren

systemctl start nginx
systemctl stop nginx
systemctl restart nginx
systemctl reload nginx          config herladen zonder herstart
systemctl status nginx          status + recente logs
systemctl enable nginx          starten bij boot
systemctl disable nginx
systemctl enable --now nginx    enable + start tegelijk

Inspecteren

systemctl list-units --type=service          actieve services
systemctl list-units --state=failed          gefaalde
systemctl is-active nginx
systemctl is-enabled nginx
systemctl cat nginx                          unit-bestand tonen
systemctl daemon-reload                      na unit-wijziging

Logs (journalctl)

journalctl -u nginx              logs van één service
journalctl -u nginx -f           live volgen
journalctl -u nginx --since "1 hour ago"
journalctl --since today
journalctl -b                    sinds laatste boot (-b -1 = vorige)
journalctl -p err                alleen errors (0-7, emerg→debug)
journalctl -n 50                 laatste 50 regels
journalctl --disk-usage
journalctl --vacuum-time=7d      ouder dan 7 dagen wissen

Unit-bestand (voorbeeld)

[Unit]
Description=Mijn app
After=network.target

[Service]
ExecStart=/usr/bin/myapp
Restart=on-failure
User=app

[Install]
WantedBy=multi-user.target

Plaats in /etc/systemd/system/, dan daemon-reload en enable --now.