Add a package to startup on Debian/ Ubuntu/ Red Hat/ CentOS

Add a package to startup on Debian/ Ubuntu/ Red Hat/ CentOS

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Linux penguin Most versions and distributions of Linux today have a start up manager application to easily set which programs are started when your Linux machine boots up. There are two distinct flavours of start up applications and a manual method for distributions without this feature installed.

Using a terminal and the command chkconfig on CentOS, Red Hat and Oracle Enterprise Linux; and update-rc.d on Debian and Ubuntu you can control which packages are available as services and which packages start with your computer.

Run Level

Before looking at the commands used to control startup services in Linux, it’s important to understand when a program should be running in relation to the current operating system state. For example, you probably don’t want your Apache service being started before you have networking.

Linux has the concept or a runlevel which dictates the state of the operating system as a number between 0 and 6 inclusive.

See my post on runlevels to understand when your application or service should be asked to start.

Start up with Red Hat, CentOS and Oracle Enterprise Linux

Controlling startup services in Linux distributions such as Red Hat Enterprise Linux (RHEL), CentOS and Oracle Enterprise Linux (OEL) is done using the chkconfig command.

See my chkconfig cheat sheet for more information on controlling startup services on RHEL based Linux.

Start up with Debian and Ubuntu

Debian and Ubuntu based Linux distributions use the command update-rc.d to control which services are started during machine boot.

For details of controlling such services, see my update-rc.d cheat sheet.

Start up for manually setting the start up services

For operating systems that are not managed by an application, such as upstart on Ubuntu, you will need to manually add the /etc/init.d/ start up script to the /etc/rc.local file.

The /etc/rc.local file contains a reference to all the services which are required on machine boot.

Run the below echo command to add a manual start up application. The application name must be the same as the /etc/init.d/ file which must exist.

To remove a service, edit the /etc/rc.local file and manually remove the service name.


update-rc.d Cheat Sheet

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Linux penguinDebian and Ubuntu use the service command to control services and update-rc.d for adding and removing services from start up. Using the service command we can start, stop, restart and display all available services. With update-rc.d we can add and remove services and add them to the Ubuntu/ Debian start up scripts. As Linux operating systems have multiple states, or runlevels, you need to make sure you add any new services to the correct runlevels. For example, you would not want to start a web service application before starting networking.

See my post on runlevels for more information about runlevels in Linux..

What services are available for startup?

Use the status-all switch to list all services which are registered with the OS and issues them a status command. You will then get one of the following displayed next to each service:

  • [ + ] – Services with this sign are currently running.
  • [ – ] – Services with this sign are not currently running..
  • [ ? ] – Services that do not have a status switch.

Sample output:

Start a service

Starting a service is done using the command service followed by the service name and the command to start the service.

Stop a service

Use the stop keyword with service to stop a service.

Check the status of a service

Each service has a status, usually running or not running. Some services, such as network, may have a different output and output more information on the service.

Remove a service

Use the remove keyword with update-rc.d to remove the service start up command for an application. You will need to use the -f switch if the applications /etc/init.d start up file exists.

 Add a service

Adding a service to Ubuntu or Debian is done with the update-rc.d command. You can specify which runlevels to start and stop the new service or accept the defaults. The init.d file will be added to the relevent rc.d startup folders.

Setting Start and Kill priority

If you need more control over when your service is asked to start and stop, you may need to set the start and kill (S and K) values.

For a given runlevel, you may have several services starting. For example, you may have apache2 and mysql both starting on runlevel 3. Ideally, you’d want mysql to start before apache2 and shutdown after apache2. In this case we need to give mysql the priority in startup, but apache2 the priority in shutdown.

When starting, the lower the number, the earlier it will start. A start priority of 10 will start before a priority of 20. When killing, it’s the opposite. A higher number will be killed before a lower number.

To set the start and kill priority we simply add them to the above update-rc.d command with the start priority first, followed by the kill priority.

The below command will start mysql first, then apache2. On shutdown, the kill will be the reverse of the start with apache2 being killed first and mysql second.

Because, in our example, both start and kill priorities are the same we can shorted the command to just

Manually set the RunLevel to Start and Kill a service

You can manually specify the Linux RunLevel that the system must be in to Start and Kill your service. See my other blog post for more information on RunLevels.

To extend the above example, we can specify exactly which RunLevel apache2 will be started and stopped.

apache2 will be started (as long as it isn’t already) when the system enters RunLevel 234 or 5 with a priority of 10. It will then be asked to stop when the system enters RunLevel 01 or 6 with a priority of 90.

Let me know in the comments if you think anything is missing.


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