systemctl for service management in Linux CLI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to start the nginx service using systemctl.

Linux CLI

sudo systemctl [1] nginx

Drag options to blanks, or click blank then click option'

Astop

Bstart

Crestart

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'stop' instead of 'start' will turn the service off.

Using 'status' only shows the service state, it doesn't start it.

The 'start' command tells systemctl to start the specified service.

2fill in blank

medium

Complete the command to check the status of the sshd service.

Linux CLI

systemctl [1] sshd

Drag options to blanks, or click blank then click option'

Arestart

Bdisable

Cenable

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'enable' or 'disable' changes startup behavior, not current status.

Using 'restart' will stop and start the service, not just show status.

The 'status' command shows if the service is running or stopped.

3fill in blank

hard

Fix the error in the command to disable the apache2 service at boot.

Linux CLI

sudo systemctl [1] apache2

Drag options to blanks, or click blank then click option'

Astatus

Bstart

Cdisable

Drestart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'stop' stops the service now but does not disable auto-start.

Using 'start' or 'restart' will start the service, not disable it.

The 'disable' command stops the service from starting automatically at boot.

4fill in blank

hard

Fill both blanks to create a command that restarts the docker service and shows its status.

Linux CLI

sudo systemctl [1] docker && systemctl [2] docker

Drag options to blanks, or click blank then click option'

Arestart

Bstart

Cstatus

Dstop

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'start' instead of 'restart' will not restart if already running.

Using 'stop' will stop the service, not restart it.

First, 'restart' restarts the service. Then, 'status' shows its current state.

5fill in blank

hard

Fill all three blanks to create a command that enables the nginx service, starts it, and then checks its status.

Linux CLI

sudo systemctl [1] nginx && sudo systemctl [2] nginx && systemctl [3] nginx

Drag options to blanks, or click blank then click option'

Adisable

Bstart

Cstatus

Denable

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'disable' instead of 'enable' will prevent auto-start.

Skipping 'start' means the service might not be running now.

Not checking 'status' leaves you unsure if the service started.

First, 'enable' sets the service to start at boot. Then, 'start' runs it now. Finally, 'status' shows if it is running.

Practice

1. What does the command systemctl start nginx do on a Linux system?

easy

A. It disables the nginx service from starting at boot.

B. It stops the nginx service.

C. It shows the status of the nginx service.

D. It starts the nginx service immediately.

Solution

1. Step 1: Understand the start action in systemctl

   The start command tells systemctl to begin running the specified service immediately.

2. Step 2: Apply to nginx service

   Using systemctl start nginx will start the nginx service right away, without affecting boot settings.

3. Final Answer:

   It starts the nginx service immediately. -> Option D

4. Quick Check:

   start means run service now [OK]

Hint: Start means run the service now, not stop or status [OK]

Common Mistakes:

• Confusing start with stop or restart
• Thinking start changes boot behavior
• Using start to check status

2. Which of the following is the correct syntax to enable a service named httpd to start automatically at boot?

easy

A. systemctl enable start httpd

B. systemctl httpd enable

C. systemctl enable httpd

D. systemctl start enable httpd

Solution

1. Step 1: Identify the correct command structure for enabling services

   The correct syntax is systemctl enable <service-name> to set a service to start at boot.

2. Step 2: Match the syntax with the httpd service

   Using systemctl enable httpd correctly enables the httpd service at boot time.

3. Final Answer:

   systemctl enable httpd -> Option C

4. Quick Check:

   enable <service> sets boot start [OK]

Hint: Enable command is followed directly by service name [OK]

Common Mistakes:

• Adding extra words like 'start' with enable
• Wrong order of commands
• Using start instead of enable for boot

3. What will be the output of the command systemctl status sshd if the SSH service is running?

medium

A. Active: active (running) since [date and time]

B. Failed to start sshd.service: Unit not found.

C. Inactive (dead)

D. No output is shown.

Solution

1. Step 1: Understand what systemctl status shows

   This command displays the current state of the service, including if it is running or stopped.

2. Step 2: Interpret the output for a running sshd service

   If sshd is running, the output includes a line like Active: active (running) since ... showing it is up.

3. Final Answer:

   Active: active (running) since [date and time] -> Option A

4. Quick Check:

   Status shows running state if active [OK]

Hint: Look for 'Active: active (running)' in status output [OK]

Common Mistakes:

• Expecting no output when service runs
• Confusing 'inactive' with running
• Thinking error means service is running

4. You run systemctl start apache2 but get the error: Failed to start apache2.service: Unit apache2.service not found. What is the most likely cause?

medium

A. The service name is incorrect or does not exist.

B. The apache2 service is already running.

C. You need to use restart instead of start.

D. You must run the command without sudo.

Solution

1. Step 1: Analyze the error message

   The error says the unit (service) apache2.service was not found, meaning systemctl cannot locate it.

2. Step 2: Identify the cause

   This usually means the service name is wrong or the service is not installed on the system.

3. Final Answer:

   The service name is incorrect or does not exist. -> Option A

4. Quick Check:

   Unit not found means wrong or missing service [OK]

Hint: Check service name spelling if 'Unit not found' error appears [OK]

Common Mistakes:

• Assuming service is running despite error
• Trying restart instead of start without checking
• Running without sudo causing permission error

5. You want to ensure the docker service starts automatically on boot and is currently running. Which two commands should you run in order, to achieve this?

hard

A. systemctl enable docker; systemctl status docker

B. systemctl start docker; systemctl enable docker

C. systemctl restart docker; systemctl disable docker

D. systemctl stop docker; systemctl enable docker

Solution

1. Step 1: Understand the goal

   We want to ensure the docker service is currently running and starts automatically on boot.

2. Step 2: Choose commands to enable boot start and ensure running

   Running systemctl start docker ensures the service is running (safe if already running), then systemctl enable docker sets it to start at boot.

3. Final Answer:

   systemctl start docker; systemctl enable docker -> Option B

4. Quick Check:

   Start first, then enable for boot start [OK]

Hint: Start service first, then enable it for boot [OK]

Common Mistakes:

• Enabling before starting service
• Stopping service when wanting it running
• Disabling service by mistake