Difference between service and systemctl in Linux

Knowing better about services and systemctl will allow you to work with them seamlessly.

What is the service command in Linux?

In Linux, the service command is a wrapper script that allows users to easily configure and interact with system services. It predates systemd and mainly works with scripts found in /etc/init.d.

Although systemctl has largely surpassed the previous meaning of service, it continues to remain relevant through many legacy features.

The change between the related initialization systems - SysVinit to systemd - was controversial, but posing challenges to the functionality of the initialization system made it necessary.

systemd starts services in parallel instead of in a serial order, making its startup time faster than SysVinit - and it provides a bit more fine-grained control over system daemons via the command-line interface (CLI).

 

What is the systemctl command in Linux?

Like services, systemctl is an extremely flexible command that allows you to enable, reload, start, stop, and check the status of services running on a Linux system.

systemctl serves as a powerful and easy-to-use interface for configuring files in systemd - for example, it only takes one or two commands to disable a service at startup using systemctl.

systemctl is backward compatible with the initialization system, SysVinit, which is mainly used with service. systemctl does not serve as a direct successor to the service, but it is much more flexible in terms of the tools it provides for managing system services.

You can accomplish tasks like creating a mask or disabling a service in just one or two lines.

Difference between service and systemctl

service and systemctl largely serve the same purpose. Many similarities between them have been intentionally included to allow users to transition more seamlessly from service to systemctl.

However, there are some differences between the two commands that you should be aware of when starting to work with the initialization system on Linux.

 

1. Different initialization systems

The most significant difference between service and systemctl is that they belong to different initialization systems. service belongs to SysVinit (System V Init), also known as the classic Linux initialization process.

systemctl belongs to systemd, the successor to SysVinit and the modern initialization process used on many Linux systems.

Since service and systemctl are part of different initialization processes, they operate on system files initialized in different directories. service works with the initialization system files contained in /etc/init.d , while systemctl works with the initialization system files contained in /lib/systemd.

Generally, the initialization system you'll encounter on out-of-the-box Linux installations is systemd - so you'll want to be familiar with using systemctl to interact with it.

If you intend to work with systems that predate or coincide with systemd's release in 2010, it doesn't hurt to get used to using the service command.

2. Compatibility

service continues to be an extremely useful command in terms of compatibility - as a wrapper command it has the ability to redirect to the service manager used on different systems. You should plan to learn and make it part of your arsenal if you will be working with a variety of Linux systems.

3. Basic Functions

One key difference between systemctl and service lies in how they work. service is a high-level command that redirects to the underlying service manager used on a particular system, meaning it is quite flexible between systems. It can redirect to /etc/init.d , upstart or even systemctl. Whereas systemctl commands interact directly with systemd.

4. Ability

In terms of what you can achieve, it's safe to say that systemctl goes beyond basic capabilities. In addition to basic functions - like starting, stopping, enabling or disabling a specific service - you can also set up advanced configurations with systemctl.

service is more limited due to its required compatibility with the underlying service managers on which it relies.