Manage Linux services on the command line (Ubuntu)

Ubuntu 18.04 uses systemd to manage services.

There are basically two commands for listing all services and manipulating the state of a certain service: service and systemctl:

• service manages System V init scripts
• systemctl controls the state of the systemd system and service manager. It is backwards compatible to System V and includes the System V services

Therefore I prefer to use systemctl.

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See which services are there

>systemctl list-units -a --type=service
  UNIT                                 LOAD      ACTIVE   SUB     DESCRIPTION                
  accounts-daemon.service              loaded    active   running Accounts Service           
  acpid.service                        loaded    active   running ACPI event daemon          
  alsa-restore.service                 loaded    active   exited  Save/Restore Sound Card State                                                   
  alsa-state.service                   loaded    inactive dead    Manage Sound Card State (restore and store)                                     
  anacron.service                      loaded    inactive dead    Run anacron jobs           
  apache-htcacheclean.service          loaded    active   running Disk Cache Cleaning Daemon for Apache HTTP Server                               
  apache2.service                      loaded    active   running The Apache HTTP Server     
  apparmor.service                     loaded    active   exited  AppArmor initialization    
  apport-autoreport.service            loaded    inactive dead    Process error reports when automatic reporting is enabled                       
  apport.service                       loaded    active   exited  LSB: automatic crash report generation                                          
  apt-daily-upgrade.service            loaded    inactive dead    Daily apt upgrade and clean activities                                          
  apt-daily.service                    loaded    inactive dead    Daily apt download activities                                                             
  avahi-daemon.service                 loaded    active   running Avahi mDNS/DNS-SD Stack    
  avahi-dnsconfd.service               loaded    inactive dead    Avahi DNS Configuration Daemon                                                  
  blk-availability.service             loaded    active   exited  Availability of block devices                                                   
  bluetooth.service                    loaded    active   running Bluetooth service   
...

• -a / --all will show you all units (without that, inactive units are omitted)
• --type=service will show you only services (there are other types Show archive.org snapshot , too)

Manage Services

To temporarily start or stop an service, you can use :

• systemctl start <name>
• systemctl stop <name>

To prevent a service from being started e.g. on boot, you have to disable it. Likewise, if you want a service to be started on boot, you have to enable it:

• systemctl enable <name>
• systemctl disable <name>

If you disable a running service, it will not be stopped. It will just not be started on the next boot. So if you want to stop a service now and disable it, you have to do both steps:

Example: Stop and disable bluetooth

>systemctl list-units -a --type=service | grep bluetooth
  bluetooth.service               loaded    active   running Bluetooth service      

>sudo systemctl stop bluetooth.service

>systemctl list-units -a --type=service | grep bluetooth
  bluetooth.service               loaded    inactive dead    Bluetooth service >sudo systemctl disable bluetooth

>sudo systemctl disable bluetooth.service
Synchronizing state of bluetooth.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install disable bluetooth
insserv: warning: current start runlevel(s) (empty) of script `bluetooth' overrides LSB defaults (2 3 4 5).
insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `bluetooth' overrides LSB defaults (0 1 6).
insserv: warning: current start runlevel(s) (empty) of script `bluetooth' overrides LSB defaults (2 3 4 5).
insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `bluetooth' overrides LSB defaults (0 1 6).

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service / System V

If you don't want to use systemd's systemctl, you can also manage the System V init scripts with the service command. Note that non system V services will not be listed and you can not manage them with service.

To get an overview which system V init scripts are available and running / not running, you can use service --status-all:

>service --status-all
 [ + ]  acpid
 [ - ]  alsa-utils
 [ - ]  anacron
 [ + ]  apache-htcacheclean
 [ - ]  apache2
 [ + ]  apparmor
 [ + ]  apport
 [ + ]  avahi-daemon
 [ + ]  avahi-dnsconfd
 [ - ]  bluetooth
...

+ means running, - means not running, ? means unknown

Manage Services

To temporarily start or stop an service, you can use:

• service <name> start
• service <name> stop

The other commands that are available with service depend on the service.