Server operations · Lesson 6 of 36 · 7 minutes

Service list

List simulated units and check nginx activity.

Open the lab Course map

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learner@clairos:~ $

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Your objectives

Hints are always available. Wrong turns never cost XP.

1
List units
Run systemctl list-units.
Hint & worked example
Inspect or change a simulated systemd service. Status, active state, and unit configuration reveal different evidence.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
systemctl list-units
```
Remember: A service can be active while an application endpoint is unhealthy; verify both layers.
2
Check nginx
Run systemctl status nginx.
Hint & worked example
Inspect or change a simulated systemd service. Status, active state, and unit configuration reveal different evidence.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
systemctl status nginx
```
Remember: A service can be active while an application endpoint is unhealthy; verify both layers.
3
Check active state
Run systemctl is-active nginx.
Hint & worked example
Inspect or change a simulated systemd service. Status, active state, and unit configuration reveal different evidence.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
systemctl is-active nginx
```
Remember: A service can be active while an application endpoint is unhealthy; verify both layers.

Understand the pattern

Read-only inspection is the safe first step in operations.

systemctl: Inspect or change a simulated systemd service. Status, active state, and unit configuration reveal different evidence.
A service can be active while an application endpoint is unhealthy; verify both layers.

Worked example and expected result

$ systemctl list-units

UNIT                  LOAD   ACTIVE
nginx.service loaded active simulated serving the simulated static learn site
ssh.service loaded active simulated accepting key-only training logins
cron.service loaded active simulated running scheduled simulated maintenance
backup.service loaded inactive simulated waiting for a configured backup target
database.service loaded inactive simulated not installed in this lab

Exit status: 0. The command completed successfully in the training fixture.

$ systemctl status nginx

nginx.service - simulated nginx
   Loaded: loaded
   Active: active
   Notes: serving the simulated static learn site

Exit status: 0. The command completed successfully in the training fixture.

$ systemctl is-active nginx

active

Exit status: 0. The command completed successfully in the training fixture.

Try a variation

Repeat this workflow in the sandbox with a different scratch filename. Keep the system fixtures unchanged and compare the observed output with your expectation before moving on.

Explain it

In “Service list”, which interpretation is safe?A service can be active while an application endpoint is unhealthy; verify both layers.A command appearing in history proves it completed successfully.A successful first check guarantees that every dependent service is healthy.

Apply it elsewhere

Before adapting the systemctl workflow from “Service list” to another server, what should you do?Paste the training paths unchanged into production.Skip output inspection whenever the command is familiar.Confirm the current directory, target identity, permissions, and the installed command behavior first.

Keep the momentum.

Complete the lab, then explain and apply the pattern.

Next: Service files Try an incident drill

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