Quickly inspect which kernel modules are loaded and why they matter. 06.04.2026 | reading time: 3 min On a running Linux system it is often useful to know which kernel modules are active; `lsmod` gives that view by listing loaded modules, their size, and how many users depend on them. Run it and read the output Try this on any Linux box to see what is loaded: ```bash $ lsmod Module Size Used by snd_hda_intel 45056 2 snd_hda_codec 131072 1 snd_hwdep 16384 1 snd_pcm 147456 2 loop 49152 1 fuse 139264 3 ``` To focus on sound drivers use a filter like `lsmod | grep snd` and you will see only the matching lines. What the columns actually mean The first column is the module name, the second is its memory footprint, and the third shows the reference count and dependent modules; a nonzero "Used by" number prevents safe removal and reveals why a module stays resident. Where lsmod gets its data `lsmod` simply reads `/proc/modules`; you can verify by comparing `cat /proc/modules` with `lsmod`, and use `modinfo` to inspect a module's parameters and license before taking action. Safe actions and troubleshooting tips Before unloading a module check dependencies and dmesg for messages; use `modprobe -r` or `rmmod` cautiously to remove modules, and run `depmod` when rebuilding dependency maps after custom module installs. Short workflow example Find a module, inspect it, then act: ```bash $ lsmod | grep vboxdrv vboxdrv 286720 0 $ sudo modinfo vboxdrv filename: /lib/modules/.../vboxdrv.ko description: VirtualBox core license: GPL $ sudo modprobe -r vboxdrv ``` This sequence shows discovery, inspection, and removal in practice. Next steps for the curious Combine `lsmod` with `lspci -k` to map devices to drivers and with `dmesg` to read kernel load logs; these combinations speed up root-cause analysis when hardware or drivers misbehave. Forward motion Mastering small utilities like `lsmod` builds a reliable troubleshooting toolkit; keep exploring kernel tools and consider certifying skills through focused preparation at bitsandbytes.academy to aim for certifications such as CompTIA Linux+ or LPIC-1. Join Bits & Bytes Academy First class LINUX exam preparation. utilities boot-process troubleshooting
