Boot problems are situations when your system does not boot properly
(does not boot to the expected runlevel and login screen).
45.3.1 Fails to Load the GRUB Boot Loader
If the hardware is functioning properly, it is possible that
the boot loader has become corrupted and Linux cannot start on the
machine. In this case, it is necessary to reinstall the boot loader.
To reinstall the boot loader, proceed as follows:
-
Insert the installation media into the drive.
-
Reboot the machine.
-
Select from the boot menu.
-
Select a language.
-
Accept the license agreement.
-
In the screen, select
and set the installation mode to
.
-
Once in the YaST System Repair module, select
then select
.
-
Restore the original settings and reinstall the boot loader.
-
Leave YaST System Repair and reboot the system.
Other reasons for the machine not booting may be
BIOS-related:
- BIOS Settings
-
Check your BIOS for references to your hard drive. GRUB might
simply not be started if the hard drive itself cannot be found
with the current BIOS settings.
- BIOS Boot Order
-
Check whether your system's boot order includes the hard disk. If
the hard disk option was not enabled, your system might install
properly, but fail to boot when access to the hard disk is
required.
45.3.2 No Login or Prompt Appears
This behavior typically occurs after a failed kernel upgrade and it is
known as a kernel panic because of the type of
error on the system console that sometimes can be seen at the final
stage of the process. If, in fact, the machine has just been rebooted
following a software update, the immediate goal is to reboot it
using the old, proven version of the Linux kernel and associated
files. This can be done in the GRUB boot loader screen during the boot
process as follows:
-
Reboot the computer using the reset button.
-
When the GRUB boot screen becomes visible, select
then press Enter.
The machine should boot using the prior version of the kernel and
its associated files.
-
After the boot process has completed, remove the newly installed
kernel and, if necessary, manually modify
/boot/grub/menu.lst to indicate the older kernel as
the default option. For some detailed information about the syntax used
in this configuration file, refer to
Section 17.0,
The Boot Loader.
Updating this file might not be necessary because automated update
tools usually modify it for you during the rollback
process.
-
Reboot.
If this does not fix the problem because the
option does not boot the computer
properly, boot the computer using the installation media. After the machine
has booted, continue with Step 3 and Step 4.
45.3.3 No Graphical Login
If the machine comes up, but does not boot into the graphical login
manager, anticipate problems either with the choice of the default
runlevel or the configuration of the X Window System.
To check the runlevel configuration, log in as the root user and check
whether the machine is configured to boot into runlevel 5 (graphical
desktop). A quick way to check this is to examine the contents of
/etc/inittab, as follows:
nld-machine:~ # grep "id:" /etc/inittab
id:5:initdefault:
nld-machine:~ #
The returned line indicates that the machine's default runlevel
(initdefault) is set to 5 and
that it should boot to the graphical desktop. If the
runlevel is set to any other number, use the YaST Runlevel Editor
module to set it to 5.
IMPORTANT:
Do not edit the runlevel configuration manually. Otherwise SuSEconfig (run
by YaST) will overwrite these changes on its next run. If you need
to make manual changes here, disable future SuSEconfig changes
by setting CHECK_INITTAB in
/etc/sysconfig/suseconfig to
no.
If the runlevel is set to 5, you might have
corruption problems with your desktop or X Windows software. Examine
the log files at /var/log/Xorg.*.log for
detailed messages from the X server as it attempted to start. If the
desktop fails during start, it might log error messages to
/var/log/messages. If these error messages hint at
a configuration problem in the X server, try to fix these issues. If
the graphical system still does not come up,
consider reinstalling the graphical desktop.
One quick test: the startx command should force the
X Window System to start with the configured defaults if the user is
currently logged in on the console. If that does not work, it should
log errors to the console. For more information about the X Window system
configuration, refer to Section 22.0,
The X Window System.
