Boot problems are situations where your NLD system does not boot properly (that is, does not boot to the expected startup runlevel and Welcome screen).
If, in fact, the hardware is functioning properly, it is possible that the boot loader has become corrupted and NLD cannot start up on the machine. In this case, it is necessary to reinstall the boot loader. This can be done using the CD-ROM install media for NLD and the AutoYaST install program, or via a network boot system which brings up AutoYaST.
Insert the Installation CD-ROM, make sure the machine’s BIOS is set to check the CD-ROM before the hard disk, then reboot using the RESET button. When the initial boot screen is shown, select . The rescue system is described in more detail in How do I recover a corrupted system? .
Other reasons for the machine not booting up might be BIOS-related:
Check your BIOS for references to your hard drive. GRUB might not be started up if the hard drive itself cannot be found with the current BIOS settings.
Check whether your system’s boot order includes the hard disk. If the hard disk option wasn’t enabled, your system might install properly but fail to boot when access to the hard disk is required.
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, then the immediate goal is to reboot it using the previous, known-good 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 hardware RESET button.
When the GRUB boot screen becomes visible, select the option and then press Enter.
The machine should boot using the previous version of the kernel and its associated files.
If option does not boot the computer properly, boot the computer using the install media.
After the boot process is completed, remove the newly installed kernel (preferably using the tool which installed it, such as YaST or Red Carpet) and, if necessary, manually modify /boot/grub/menu.lst to indicate the previous kernel as the default option.
For detailed information on the syntax used in this configuration file, see “Section 8.4: Booting with GRUB” in the SUSE LINUX Enterprise Server 9 Administration Guide
Updating this file might not be necessary, as automated update tools usually modify it for you during the rollback process.
Reboot.
If the machine comes up but doesn’t 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 - graphic desktop. A quick way to check this is to examine the contents of /etc/inittab by entering
nld-machine:~ # grep “id:” /etc/inittab id:5:initdefault: nld-machine:~ #
The returned line ideally indicates that the machine’s default runlevel (initdefault) is set to 5 and that it should, in fact, boot to the graphics 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. YaST or, rather, SuSEconfig overwrites these changes on its next run. If you need to make manual changes here, you can disable the SuSEconfig overwrites 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 logfiles at /var/log/XFree86.*.log for detailed messages from the X server as it attempts to start. If the desktop fails during startup, it might log error messages to /var/log/messages. If these error messages hint at a configuration problem at the X server, try to fix these issues. If the graphical system still does not come up, it might be time to consider reinstalling the graphical desktop.
The startx command should force the X Windows system to start with the configured defaults if the user is currently logged in at the console. If that does not work, it should log errors to the console.