I'm having difficulty finding any sort of comprehensive list and description of parameters available in /boot/grub/grub.conf file for the kernel line. I've googled around but haven't found a good reference for this information.


I don't think there is any comprehensive list. In addition to what the kernel does (see kernel-parameters.txt), any program can look at /proc/cmdline and extract information, and many do. In RHEL7 (and Fedora, etc.), systemd looks for a number of systemd. parameters there — you will find these documented in the Kernel Command Line section of the systemd(1) man page.

Some of these and a few others are documented in the kernel-command-line(7) man page.

  • Hmmmm...../proc/cmdline simply provides the same information as that in the /boot/grub/grub.conf. BTW, the kernel-command-line man page is a RHEL/Centos 7 item. – mdpc Dec 15 '16 at 1:33
  • kernel-command-line man page is from systemd, so you'll see it in RHEL 7 and also Fedora, Arch, Debian, openSUSE, Ubuntu, etc. – mattdm Dec 15 '16 at 1:55
  • 2
    Saying it's the same information as in grub.conf is... a little upside down. The bootloader is what gives the kernel its command line, so the default will be in its configuration. But, you can also specify different options at boot time — this is frequently the case for debug and rescue options. – mattdm Dec 15 '16 at 1:57

The kernel-doc package should provide the list you seek.

yum install kernel-doc

After installation, look in the kernel-parameters.txt file:

less /usr/share/doc/kernel-doc-<version>/Documentation/kernel-parameters.txt

Be sure to change <version> to your version (possibly 2.6.32). My system uses 2.6.18 (RHEL 5.X version).

kernel.org may provide a more complete list of kernel parameters and definitions.

  • I've seen that one in my google trek, but it is not complete. EX: rhgb or crashkernel=auto or biosdevname...etc....etc.....Where do I go to discover these and other possibly hidden gems? – mdpc Dec 15 '16 at 1:03
  • @mdpc - anyone writing a driver uses their own parameters that can be passed to the kernel so unless you read the documentation for all modules and whatnot I'm afraid there is no such comprehensive list – don_crissti Dec 15 '16 at 1:25
  • How do you know which are passed to other modules and which are processed by the kernel? I might agree with you but for the example crashkernel parameter is defined in the document but not the auto setting. – mdpc Dec 15 '16 at 1:28

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