depmod

Additional Notes

depmod analyzes installed kernel modules and writes dependency files used by modprobe. These files help the system load required modules automatically.

It is usually run automatically after installing kernel modules, but administrators may run it manually after adding custom modules.

Syntax

depmod [options] [kernel-version]

Parameters

• kernel-version: Kernel version whose module directory should be processed. Defaults to the running kernel.
• options: All, quick, base-directory, and error-reporting controls.

Common Options

• -a: Process all modules for the selected kernel version.
• -A: Only update if module files are newer than dependency files.
• -e: Report unresolved symbols.
• -n: Print output to standard output instead of writing files.
• -b DIR: Use DIR as a basedir, useful for packaging or chroot-style work.
• -F System.map: Use a System.map file for symbol checks.

Examples

sudo depmod -a

Regenerate module dependencies for the running kernel.

sudo depmod -a 6.8.0-31-generic

Process modules for a specific kernel version.

depmod -n | less

Preview generated dependency information.

modprobe module_name

Load a module using dependency information.

Practical Notes

• Run depmod after installing custom modules into /lib/modules/KERNEL_VERSION/.
• The kernel version must match the module directory.
• Use modinfo and modprobe for related module inspection and loading.