Listing Modules

Listing Modules

Though the Linux kernel can be completely monolithic, it’s really not proactical in many consumer-grade systems. The size of a kernel with all possible modules compiled directly in simply prevents it from being feasible. For that reason, many of the modules, or device drivers, can be dynamically loaded and unloaded in Linux, to be used only as needed.

So let’s say that the first time you fire up your new Linux system, you have no sound. Sound modules are, perhaps, the most commonly used in Linux. How do you even begin to troubleshoot the problem? It seems like you’d need to know if the sound module has even been loaded.

That’s the purpose of the lsmod command. Just like its shorter counterpart, ls, lsmod is a [l]i[s]t command. In this case, it lists all the loaded modules.

To display a listing of all loaded modules, simply run the lsmod command from the command line. You’ll be returned a list of the modules, their sizes, and any referring modules. You’ll also see which modules will be dynamically unloaded when not in use - they’re denoted with the (autoclean) notation.

If you’re having problems with modular devices such as sound cards, the lsmod is the place to start when troubleshooting.