What location is prioritized for SYSTEMD units controlled by the sysadmin?

The directory designated for system administrator-controlled SYSTEMD units is /etc/systemd/system/. This location takes precedence when managing systemd services and units because it is specifically intended for local overrides and custom configurations made by the sysadmin.

When a unit file in /etc/systemd/system/ has the same name as one in other directories like /usr/lib/systemd/system/, the system will prioritize the one in /etc over the others. This allows system administrators to modify service configurations, enable or disable services, or create additional service files without affecting the original files installed by the system or other package managers.

In contrast, /usr/lib/systemd/system/ contains unit files provided by installed packages and should not be modified directly by users. The /run/systemd/system/ directory is used for runtime data and transient unit files, not for permanent changes. Lastly, /var/lib/systemd/system/ is not a standard or common location for systemd unit files, making /etc/systemd/system/ the correct answer for prioritized directory management by system administrators.