From Fedora Project Wiki


Debugging

All bug reports

In all cases, the following should be mentioned and attached to your bug report:

The exact kernel command line used!

An copy of /etc/fstab

cp /etc/fstab ~USER/Desktop/fstab.txt

The output of dmsetup ls --tree.

 dmsetup ls --tree > ~USER/Desktop/dmsetup.txt

If using an raid device the output of cat /proc/mdstat.

 cat /proc/mdstat > ~USER/Desktop/mdstat.txt

Preparing your system for debugging

To be successful

Redirect all non-interactive stuff output to /dev/kmsg that

exec >/dev/kmsg 2>&1 </dev/console

Create the image debug enable.

-a debug

Boot with debug enable.

rdinitdebug rdnetdebug
Note.png

Dracut debugging kernel command parameters

rdinitdebug
Note.png
set -x for the dracut shell
rdbreak=[pre-udev|pre-mount|mount|pre-pivot|]
Note.png
drop the shell on defined breakpoint
rdudevinfo
Note.png
set udev to loglevel info
dudevdebug
Note.png
set udev to loglevel debug
rdnetdebug
Note.png
debug network scripts in dracut