Where are systemd unit files typically located?

• A. /lib/systemd/system
• B. /usr/lib/systemd/system and /etc/systemd/system
• C. /etc/init.d
• D. /var/lib/systemd

Answer: (B)

Systemd unit files are kept in locations that separate packaged units from administrator-provided ones. The standard place for files installed by packages is /usr/lib/systemd/system, while /etc/systemd/system is where you add or override units created by the administrator. Systemd will read units from both locations, and if a unit exists in both, the version in /etc/systemd/system takes precedence, allowing local customization without altering the packaged unit.

The other paths mentioned aren’t for native systemd unit files: /etc/init.d holds legacy SysV init scripts, and /var/lib/systemd is used for state data, not for unit definitions.