This section lists some of the problems frequently encountered when booting with GRUB and a short description of possible solutions. Some of the problems are covered in articles in the Support Database at http://en.opensuse.org/SDB:SDB. Use the search dialog to search for keywords like GRUB, boot, and boot loader.
XFS leaves no room for stage1 in the partition boot block. Therefore, do not specify an XFS partition as the location of the boot loader. This problem can be solved by creating a separate boot partition that is not formatted with XFS.
GRUB checks the geometry of connected hard disks when the system is booted. Sometimes, the BIOS returns inconsistent information and GRUB reports a GRUB Geom Error. If this is the case, use LILO or update the BIOS. Detailed information about the installation, configuration, and maintenance of LILO is available in the Support Database under the keyword LILO.
GRUB also returns this error message if Linux was installed on an additional hard disk that is not registered in the BIOS. stage1 of the boot loader is found and loaded correctly, but stage2 is not found. This problem can be remedied by registering the new hard disk in the BIOS.
During the installation, YaST may have incorrectly determined the boot sequence of the hard disks. For example, GRUB may regard the IDE disk as hd0 and the SCSI disk as hd1, although the boot sequence in the BIOS is reversed (SCSI before IDE).
In this case, correct the hard disks during the boot process with the help of the GRUB command line. After the system has booted, edit device.map to apply the new mapping permanently. Then check the GRUB device names in the files /boot/grub/menu.lst and /boot/grub/device.map and reinstall the boot loader with the following command:
grub --batch < /etc/grub.conf
Some operating systems, such as Windows, can only boot from the first hard disk. If such an operating system is installed on a hard disk other than the first hard disk, you can effect a logical change for the respective menu entry.
... title windows map (hd0) (hd1) map (hd1) (hd0) chainloader(hd1,0)+1 ...
In this example, Windows is started from the second hard disk. For this purpose, the logical order of the hard disks is changed with map. This change does not affect the logic within the GRUB menu file. Therefore, the second hard disk must be specified for chainloader.