CentOS 7 /RHEL7: Enable/Disable A Service

I would like to configure a service to be started automatically while system startups up. How Do I enable a service under CentOS 7 or RHEL operating systme? How can I disable a service unit at boot time in centos 7?

​In CentOS 7 or RHEL 7 system, you need to use “systemctl” command with “enable” or “disable” options to enable or disable service at boot time instead of “chkconfig” command.

CentOS 7 /RHEL7 Enable/Disable A Service

CentOS 7 Enabling A Service

To enable a service unit to be automatically started while system startups up, issue the following command:

systemctl enable <service_name>.service

OR

systemctl enable <service_name>

Example: To enable httpd service via running the following command:

#systemctl enable httpd.service

Outputs:

[root@devops /]# systemctl enable httpd.service

ln -s '/usr/lib/systemd/system/httpd.service' '/etc/systemd/system/multi-user.target.wants/httpd.service'

[root@devops /]# ls -l /etc/systemd/system/multi-user.target.wants/httpd.service

lrwxrwxrwx. 1 root root 37 Dec 12 07:36 /etc/systemd/system/multi-user.target.wants/httpd.service -> /usr/lib/systemd/system/httpd.service

From the above output, you can see that this command will create approriate symbolic links to the “/usr/lib/systemd/system/httpd.service“.

Note: if the symbolic link exists already, this command won’t rewrite this soft link. so if you want to recreate symbolic link for enabling service, issue the following “reenable” option, type:

systemctl reenable <service_name>.service

To reenable httpd service, type:

#systemctl reenable httpd.service

Outputs:

[root@devops /]# systemctl reenable httpd.service

rm '/etc/systemd/system/multi-user.target.wants/httpd.service'

ln -s '/usr/lib/systemd/system/httpd.service' '/etc/systemd/system/multi-user.target.wants/httpd.service'

CentOS 7 Disabling A Service

To disable a service to be not started automatically at boot time by running the systemctl command with “disable” option, type:

systemctl disable <service_name>.service

OR

systemctl disable <service_name>

For example: disabling apache web service, enter:

#systemctl disable httpd.service

Outputs:

[root@devops /]# systemctl disable httpd.service

rm '/etc/systemd/system/multi-user.target.wants/httpd.service'

This command will remove appropriate symbolic links to “/usr/lib/systemd/system/httpd.service”.

[root@devops /]# ls -l /etc/systemd/system/multi-user.target.wants/httpd.service

ls: cannot access /etc/systemd/system/multi-user.target.wants/httpd.service: No such file or directory

done….