Useful kernel parameters

This is just a memory aid.

Most kernel parameters are documented at

Kernel parameters: doc/html/latest/admin-guide/kernel-parameters.txt

  • boot_delay=n    delay n milliseconds between printk. n<10000
  • console=ttyS1 =ttyUSB0
  • debug                     enable kernel debugging
  • module.dnydbg     see Documentation/dynamic-debug-howto.txt
  • enforcing=0/1  initial SELinux enforcing status
  • ignore_loglevel  ALL printk to the console
  • loglevel=0-7  All printk <n will be printed to console
  • module_blacklist=  comma separated
  • S single mode
  • selinux=0/1 disable selinux
  • apparmor=0/1 disable apparmor

Dracut stuff, at pub/linux/utils/boot/dracut/dracut.html

  • rd.cmdline=ask   ask for addition parameters
  • rd.driver.blacklist=
  • rd.debug
  • rd.udev.debug
  • rd.luks.uuid=luks-e71d37f5-8961-48eb-b821-64fddbdeabe6
  • rd.luks.key=<keypath>.<keydev>.<luksdev>

<keypath> required, path to key file. If ends in .gpg you’re prompted for a password

<keydev> device, can be /dev/, or UUID= or LABEL=.  UUID can be just first part.

<luksdev> only need if there are multiple luks devices, this says which one this spec applies to.