modules-load
also: modules-load.d
A systemd configuration mechanism that automatically loads kernel modules at boot time by reading directives from files in /etc/modules-load.d/ and /usr/lib/modules-load.d/.
modules-load is a systemd feature that enables automatic kernel module loading without requiring manual modprobe commands or static entries in /etc/modprobe. Configuration files use a simple line-based format where each line specifies a module name to load.
Configuration files are stored in drop-in directories: /etc/modules-load.d/ for system-wide settings and /usr/lib/modules-load.d/ for vendor defaults. Files should have a .conf extension.
Example: creating /etc/modules-load.d/custom.conf with the content overlay will automatically load the overlay filesystem module at boot. This is commonly used for container runtimes, network drivers, or hardware-specific modules.