# Systemd

## Servicios

opciones disponibles para un servicio (apache2)
```
systemctl stop apache2
systemctl start apache2
systemctl restart apache2
systemctl reload apache2
systemctl reload-or-restart apache2
systemctl status apache2
systemctl is-active apache2
systemctl is-enabled apache2
systemctl is-failed apache2
systemctl cat apache2.service
systemctl list-dependencies apache2.service
systemctl enable apache2
systemctl disable apache2
```

editar servicios
```
systemctl edit apache2.service
systemctl edit --full apache2.service
```

# Generales

estado del sistema
```
systemctl is-system-running
systemctl status
systemctl list-units --failed
```

opciones generales de systemd
```
systemctl list-units
systemctl list-units --failed
systemctl list-units --all
systemctl list-units --all --state=inactive
systemctl list-units --all --state=active
systemctl list-units --type=service
```

ver servicios configurados al arrancar
```
systemctl list-unit-files
```

opciones generales del sistema
```
systemctl halt
systemctl poweroff
systemctl reboot
```

ver dns del sistema
```
systemd-resolve --status
```

resetear conexiones de audio/mic (para auriculares)

```
systemctl --user restart pulseaudio.service
```

# Logs

logs
```
journalctl
journalctl -b          # desde el ultimo boot
journalctl -k          # kernel - dmesg
journalctl -p err -b   # errores desde el ultimo boot
journalctl -n 20       # ultimas 20 lineas
journalctl -x          # agrega textos explicativos
journalctl -e          # al final del less
journalctl --since yesterday
journalctl --since "2015-01-10" --until "2015-01-11 03:00"
journalctl -u apache2.service
journalctl -u apache2.service -u mysql.service
journalctl _UID=33
journalctl --no-pager  # tira a consola sin el less
```

# masked

'mask' is a state of unit files which is considered as the "third level of off" (stop-1st, disable-2nd, mask-3rd). The services labeled as masked can neither be started manually (using the start command) nor by systems (at system boot). Therefore, use caution when employing the systemctl mask command on a service.