Checking and Manipulating Conguration Files
As an example for a conguration that might be xed using the rescue system,
imagine you have a broken conguration le that prevents the system from booting
properly. You can x this using the rescue system.
To manipulate a conguration le, proceed as follows:
1 Start the rescue system using one of the methods described above.
2
To mount a root le system located under /dev/sda6 to the rescue system,
use the following command:
mount /dev/sda6 /mnt
All directories of the system are now located under /mnt
3 Change the directory to the mounted root le system:
cd /mnt
4 Open the problematic conguration le in the vi editor. Adjust and save the
conguration.
5 Unmount the root le system from the rescue system:
umount /mnt
6 Reboot the machine.
Repairing and Checking File Systems
Generally, le systems cannot be repaired on a running system. If you encounter
serious problems, you may not even be able to mount your root le system and the
system boot may end with a “kernel panic”. In this case, the only way is to repair
the system from the outside. The rescue system provides all tools needed for a
manual le system check or repair. It contains the utilities to check and repair the
btrfs, ext2, ext3, ext4, reiserfs, xfs, dosfs, and vfat le systems.
Accessing the Installed System
If you need to access the installed system from the rescue system, you need to do
this in a change root environment. For example, to modify the boot loader congura-
tion, or to execute a hardware conguration utility.
To set up a change root environment based on the installed system, proceed as fol-
lows:
1 First mount the root partition from the installed system and the device le
system (change the device name to your current settings):
Help and Troubleshooting 265
