Operation Manual

Checkingand Manipulating ConfigurationFiles
As an example for a configurationthat might be fixed using the rescuesystem,
imagine you have a broken configurationfile that prevents the systemfrom booting
properly. You can fix this using the rescuesystem.
To manipulate a configurationfile, proceed as follows:
1 Start the rescuesystemusing one of the methodsdescribedabove.
2
To mounta root file systemlocatedunder
/dev/sda6
to the rescuesystem,
use the following command:
mount /dev/sda6 /mnt
All directoriesof the system are now located under
/mnt
3 Changethe directoryto the mountedroot file system:
cd /mnt
4 Open the problematicconfigurationfile in the vi editor. Adjustand save the
configuration.
5 Unmountthe root file systemfrom the rescuesystem:
umount /mnt
6 Rebootthe machine.
Repairing and CheckingFile Systems
Generally,file systemscannot be repaired on a running system.If you encounter
seriousproblems,you may not even be able to mount your root file systemand the
systemboot may end with a “kernel panic”. In this case,the only way is to repair
the system from the outside. The rescue systemprovides all tools neededfora
manual file systemcheckor repair. It containsthe utilities to checkand repair the
ext2
,
ext3
,
ext4
,
reiserfs
,
xfs
,
dosfs
,and
vfat
file systems.
Accessingthe Installed System
If you need to accessthe installed systemfrom the rescuesystemto, you need to
do this in a changeroot environment.For example,to modify the boot loaderconfi-
guration, or to execute a hardware configurationutility.
To set up a change root environment based on the installedsystem,proceed as fol-
lows:
1 Firstmountthe root partitionfrom the installedsystemand the devicefile
system(change the device name to your current settings):
108 Start-Up