Kernel and module parameters

Individual kernel parameters or module parameters are single keywords, or keyword-value pairs of the form keyword=<value> with no blank. Blanks separate consecutive parameters.

Kernel parameters and module parameters are encoded as strings of ASCII characters. For tape or the z/VM® reader as a boot device, the parameters can also be encoded in EBCDIC.

Use kernel parameters to configure the base kernel and any optional kernel parts that have been compiled into the kernel image. Use module parameters to configure separate kernel modules. Do not confuse kernel and module parameters. Although a module parameter can have the same syntax as a related kernel parameter, kernel and module parameters are specified and processed differently.

Where possible, this document describes kernel parameters with the device driver or feature to which they apply. Kernel parameters that apply to the base kernel or cannot be attributed to a particular device driver or feature are described in Selected kernel parameters. You can also find descriptions for most of the kernel parameters in Documentation/admin-guide/kernel-parameters.txt in the Linux source tree.

Separate kernel modules must be loaded before they can be used. Many modules are loaded automatically by Red Hat® Enterprise Linux 8.6 when they are needed. To keep the module parameters in the context of the device driver or feature module to which they apply, this document describes module parameters as part of the syntax you would use to load the module with modprobe.

To find the separate kernel modules for Red Hat Enterprise Linux 8.6, list the contents of the subdirectories of /lib/modules/<kernel-release> in the Linux file system. In the path, <kernel-release> denotes the kernel level. You can query the value for <kernel-release> with uname -r.