Howto: Linux Add or Remove a Linux Kernel Modules / Drivers

Posted on in Categories , , , last updated May 16, 2013

How do I add or remove hardware device driver (module) from running Linux kernel?

Linux systems comes with the modprobe command, to add and remove modules from the Linux Kernel. Please note that:

=> Under MS-Windows you use term device driver for modules.

=> Under Linux you use term modules for device drivers.

=> The Linux kernel has a modular design.

=> At boot time, only a minimal resident kernel is loaded into memory.

=> If you add new hardware you need to add driver i.e. modules.

=> The modprobe command intelligently adds or removes a module from the Linux kernel

=> Usually, all Linux kernel modules (drivers) are stored in the module directory located that /lib/modules/$(uname -r) directory. To see current modules, type:
$ ls /lib/modules/$(uname -r)

build                modules.ccwmap       modules.order
initrd               modules.dep          modules.pcimap
kernel               modules.dep.bin      modules.seriomap
misc                 modules.devname      modules.softdep
modules.alias        modules.ieee1394map  modules.symbols
modules.alias.bin    modules.inputmap     modules.symbols.bin
modules.builtin      modules.isapnpmap    modules.usbmap
modules.builtin.bin  modules.ofmap        updates

Use the following command to list all drivers for various devices:
$ ls /lib/modules/$(uname -r)/kernel/drivers/
Sample outputs:

Fig.01: Device drivers on my Linux based system
Fig.01: Device drivers on my Linux based system

Task: Add a Module (driver) Called foo

Type the following command as root user:
# modprobe foo
In this example, I am loading a module called i8k, enter:
# modprobe -v i8k
Sample outputs:

insmod /lib/modules/3.5.0-30-generic/kernel/drivers/char/i8k.ko 

Find out info about loaded module

You need to use the modinfo command to see information about a Linux Kernel module. The syntax is:
# modinfo -v {module-name-here}
# modinfo i8k

Sample outputs:

Fig.02: Displaying information about a Linux Kernel module called i8k
Fig.02: Displaying information about a Linux Kernel module called i8k

Task: List all loaded modules

Use the lsmod command to show the status of modules in the Linux Kernel:
# lsmod
Sample outputs:

Module                  Size  Used by
smbfs                  75465  0
md5                     5953  1
ipv6                  284193  10
ipt_TOS                 4033  2
iptable_mangle          4545  1
ip_conntrack_ftp       74801  0
ip_conntrack_irc       74033  0
ipt_REJECT              8897  43
ipt_LOG                 8513  2
ipt_limit               4033  6
iptable_filter          4673  1
ipt_multiport           3521  4
ipt_state               3393  16
ip_conntrack           54297  3 ip_conntrack_ftp,ip_conntrack_irc,ipt_state
ip_tables              21825  8 ipt_TOS,iptable_mangle,ipt_REJECT,ipt_LOG,ipt_limit,iptable_filter,ipt_multiport,ipt_state
i2c_dev                13889  0
i2c_core               28865  1 i2c_dev
dm_mirror              32721  0
dm_mod                 68609  1 dm_mirror
button                  9313  0
battery                11465  0
ac                      6985  0
ohci_hcd               24529  0
ehci_hcd               33989  0
tg3                   109381  0
floppy                 66065  0
ext3                  137937  2
jbd                    69105  1 ext3
sata_svw               10053  3
libata                 78345  1 sata_svw
sd_mod                 19393  4
scsi_mod              141457  2 libata,sd_mod

Task: Remove a module called foo

Pass the -r option to modprobe command to remove a module, type:
# modprobe -r foo
You can also use the rmmod command, which is simple program to remove a module from the Linux Kernel:
# rmmod foo

Recommended readings
  • man pages – modinfo, lsmod, insmod, and modprobe

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

21 comment

  1. when the system is rebooted the module inside the kernel will not be present.But i want the modules to be seen permenently.what should i do.

  2. Hi there…
    I am trying to remove TCP IP from a linux kernel, and want to recompile the LINUX kernel. But being a novice with the administrations of the linux (UBUNTU 10.4), I know a little about it. Agter recompilation can I again design mu own TCPIP using the C language code?
    Guys please help me out…waiting for the reply .

  3. Thanks for this very short but very clear information. That helps me to understand the concept (of add or remove module on Linux) very much.

    One question remain: how do we check to know what modules are available to add on a existing system?

    Thank you in advance!

    1. One question remain: how do we check to know what modules are available to add on a existing system?

      cd to /lib/modules/$(uname -r) directory and you can see the list of available modules (run as root):

      cd /lib/modules/$(uname -r)
      ls -l

      The following will list all drives

      find /lib/modules/$(uname -r) -type f -iname "*.ko"

      To find out more info about a module called foo:

      modinfo foo

      Hope this helps!

  4. Hi
    thanks for your comments, I am trying to write a printer driver for linux, what should I do?

    Please help me on this task.

  5. Does anyone knows step by step guide for how to install ip_conntrack support into kernel Linux linux #1 SMP Wed Nov 23 13:57:33 UTC 2011 i686 i686 i386 GNU/Linux

  6. I am unable to remove the following modules after issuing the commands.
    $ rmmod usbhid and
    $rmmod hid..

    After issuing the commands the modules are not shown in “lsmod” but as soon as a device is added they again get loaded.

    Any suggestions…

  7. Hello there. I have an old computer Celeron, 128MB RAM and 28MB of VGA. What I want to do is keep the drivers that are needed for my system. Like if I use the Realtek Chipset for Network Card why should the Atheros driver be present on the system? Is there any way to accomplish this task?

  8. I have a serious problem, my Linux does not have these comands:
    …etc… and also has not a lot of typical commands

    And there is no /dev/loop*

    And mount -o loop blablabla bleble say incorrect option, does not undertand loop.

    Of course, all problem seem that Kernel has no loop device support.

    How can i fix it?

    Please have in mind Kernel is on ROM (a chip not writteable), it is not a flasheable chip, i can not modify it on any way, … read only memory chip!!

    I wish if it could be possible to add loop device support at run time as a module…

    But it does not have modprobe command… neither a lot of clasic Linux commands… so i got to fail.

    Need some help, i am not an expert.

    Step 1: try to create /dev/loop0 (it does not exists) with mknod but mknod command not found

    Try to add such coomands with apt-get, wget, etc… all says such commands not exists

    I am getting mad…

    Please note it is an ARM processor based, and Kernel is on a ReadOnly chip not flashable.

    Thanks in advance for any help… i am getting really mad…

  9. If I were you, rather than finding Linux Kernel modulos to have “uname”, “modprobe”, “man” recovered (maybe you have played around some kernel rebuild and screwed up some basic binaries?), I will re-install the entire Linux OS from scratch. You can download CentOS (Red Hat) or SUSE, Fedora or whatever Linux to have all these basic utilities included.

  10. trying to add slcan module to kernel 2.6.32-504.30.3.el6.i686 but having problems with the following response … question is how to get it added

    FATAL: Module slcan not found.

  11. i want to know how many mouldes in linus and brief explanation of them.i will glad if my question is been answered.

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