LFCS Certification System Service Management (systemd) 5

Question 1

What is the correct way to make a custom unit file survive system package upgrades?

Accepted Answer

Place it in /etc/systemd/system/

Answer

Files in `/etc/systemd/system/` are managed by the administrator and take precedence over vendor files in `/usr/lib/systemd/system/`, surviving package upgrades.

Question 2

A service has `KillMode=control-group` set. What happens when systemd stops it?

Accepted Answer

All processes in the service's cgroup receive the kill signal

Answer

`KillMode=control-group` (the default) sends the kill signal to all processes in the unit's cgroup, preventing orphan processes.

Question 3

Which directive in a unit file's [Unit] section defines a hard dependency where the unit will fail if the dependency is not met?

Accepted Answer

Requires=

Answer

`Requires=` creates a hard dependency: if the required unit fails to start, the dependent unit also fails, unlike `Wants=` which is a soft dependency.

Question 4

You want to run a one-shot script at every boot without keeping a running process. Which service `Type=` is most appropriate?

Accepted Answer

Type=oneshot

Answer

`Type=oneshot` tells systemd the service's main process is expected to exit after completing its task, and systemd waits for it to finish before proceeding.

Question 5

Which command shows the overall boot time broken down into firmware, loader, kernel, and userspace phases?

Accepted Answer

systemd-analyze time

Answer

`systemd-analyze time` outputs the total boot time split into firmware, boot loader, kernel initialization, and userspace (initrd + system) phases.

LFCS Certification Practice Test

LFCS Certification Practice Test

LFCS Certification System Service Management (systemd) 5