1. Managing Core System Configuration
  2. Managing Kernel Modules
  3. About Module Parameters

About Module Parameters

To modify a module's behavior, specify parameters for the module in the modprobe command: 

sudo modprobe module_name parameter=value ...

Separate multiple parameter and value pairs with spaces. Array values are represented by a comma-separated list, for example: 

sudo modprobe foo arrayparm=1,2,3,4

Alternatively, change the values of some parameters for loaded modules and built-in drivers by writing the new value to a file under /sys/module/module_name/parameters, for example: 

echo 0 | sudo tee /sys/module/ahci/parameters/skip_host_reset

Configuration files (/etc/modprobe.d/*.conf) specify module options, create module aliases, and override the usual behavior of modprobe for modules with special requirements. The /etc/modprobe.conf file that was used with earlier versions of modprobe is also valid if it exists. Entries in the /etc/modprobe.conf and /etc/modprobe.d/*.conf files use the same syntax.

The following are commonly used commands in modprobe configuration files:

alias

Creates an alternative name for a module. The alias can include shell wildcards. To create an alias for the sd-mod module: 

alias block-major-8-* sd_mod
blacklist

Ignore a module's internal alias that's displayed by the modinfo command. This command is typically used in the following conditions:

  • The associated hardware isn't required.

  • Two or more modules both support the same devices.

  • A module invalidly claims to support a device.

For example, to demote the alias for the frame-buffer driver cirrusfb, type: 

blacklist cirrusfb

The /etc/modprobe.d/blacklist.conf file prevents hotplug scripts from loading a module so that a different driver binds the module instead regardless of which driver happens to be probed first. If it doesn't already exist, you must create it.

install

Runs a shell command instead of loading a module into the kernel. For example, load the module snd-emu10k1-synth instead of snd-emu10k1: 

install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 && /sbin/modprobe snd-emu10k1-synth
options

Defines options for a module. For example, to define the nohwcrypt and qos options for the b43 module, type: 

options b43 nohwcrypt=1 qos=0
remove

Runs a shell command instead of unloading a module. To unmount /proc/fs/nfsd before unloading the nfsd module, type: 

remove nfsd { /bin/umount /proc/fs/nfsd > /dev/null 2>&1 || :; } ;
/sbin/modprobe -r --first-time --ignore-remove nfsd

For more information, see the modprobe.conf(5) manual page.