Linux Systemctl Service Management Tutorial – POFTUT

Linux Systemctl Service Management Tutorial

Hi, today we will learn managing Linux services with systemd or systemctl. While Linux kernel booting, it loads drivers, mount file systems, starting memory management, creating system calls etc. But after that what? Linux starts an init process to create further system and user services and processes. To manage system services we need a tool which is generally systemd. With this tools we can set a services status, see it.Also we can change mount and system snapshot issues. But we will only look for service management side. By the way a services is a daemon which works background to complete his workloads. Apache, mysql etc are services.

List Existing Services

To see all running services run systemctl command. As you can see from output systemctl list devices,ttys,services,files system related service.

List Existing Services

List Existing Services

Print/Display Service Status

To see status of service use systemctl status. You can see process id traffic info, service name and latest logs.

Print/Display Service Status

Print/Display Service Status

Start Service

To start a services use systemctl start httpd. If it starts accordingly it shows nothing as output.

Stop Service

We can stop a service or daemon with the stop option to the systemctl command. In this example we will stop service named httpd which is named apache2 in  Ubuntu.

Start Service At Boot

To enable a service start in startup use systemctl enable httpd. It creates a softlink for current initlevel which is multi-user

LEARN MORE  How To Start, Stop and Get Status of Linux Service With Systemd?

Disable Service Startup At Boot

To disable a service startup systemctl disable httpd

Print Service Startup Status At Boot

Check a service about enabled status

In Linux,UNIX systems there is two run level which is mostly used. Run level is the status of a system for example if you do not need graphic interface but need networking an multi user you use runlevel3 or multiuser runlevel, if you need gui then you change to runleve 5 or graphical. In these runlevels appropriate services started.

First look current runlevel.

Change to multi user run level which is current

Change to graphical runlevel.

Set Default System Run Level

To change default start run level or target

Create Service Snapshot

To create a snapshot of current system and services status use systemctl snapshot. This is not disk snapshot just service snapshot. Say you start 25 services  and do not want to do all time you can snapshot this and than easily recall the snapshot. If you want you can give name of the snapshot after snaphot command

LEARN MORE  Linux chkconfig Command Tutorial with Examples

Revert Service To Snapshot

We can reload or revert to the snapshot with the isolate command like below.

Delete Service Snapshot

Existing snapshots can be deleted with the delete option. In this example we will delete snapshot snapshot-1.snapshot .

Show Service Parameters and Details

To see service parameters and details which resides in service file.

Show Service Parameters and Details

Show Service Parameters and Details

1 Response

  1. 14/10/2017

    […] Linux Systemctl Tutorial […]

Leave a Reply

Your email address will not be published. Required fields are marked *

Enjoy this blog? Please spread the word :)