Next: 2.2.2.5 The boot prompt
Up: 2.2.2 LILO
Previous: 2.2.2.3 LILO in the
Contents
The most common BIOS restrictions that affect LILO are the limitation
to two hard disks and the inability to access more than 1024 cylinders
per disk. LILO can detect both conditions, but in order to work around
the underlying problems, manual intervention is necessary.
The drive limit does not exist in every BIOS. Some modern motherboards
and disk controllers are equipped with a BIOS that supports more (typically
four) disk drives. When attempting to access the third, fourth, etc.
drive, LILO prints a warning message but continues. Unless the BIOS
really supports more than two drives, the system will not be able
to boot in that case
There are four approaches of how such problems can be solved:
- use of a different partition which is on an accessible disk and which
does not exceed the 1024 cylinder limit. If there is only a DOS partition
which fulfills all the criteria, that partition can be used to store
the relevant files.
- rearranging partitions and disks. This is typically a destructive
operation, so extra care should be taken to make good backups.
- if the system is running DOS or Windows 95, LOADLIN can be used instead
of LILO.
- if all else fails, installation of a more capable BIOS, a different
controller or a different disk configuration.
LILO depends on the BIOS to load the following items:
- /boot/boot.b
- /boot/map (created when running /sbin/lilo)
- all kernels
- the boot sectors of all other operating systems it boots
- the startup message, if one has been defined
Typically, what most Linux distributions do, is create a small /boot
partition at the beginning of the drive from 50-100Mb. This insures
that the required files will be within the 1024 cylinder boundary.
Other strategies include using Logical Block Addressing (LBA), which
``fools'' the bios into seeing the disc geometry with 1024 cylinders
or less.
Next: 2.2.2.5 The boot prompt
Up: 2.2.2 LILO
Previous: 2.2.2.3 LILO in the
Contents
