Next: Disk parameter table
Up: Disk geometry
Previous: Obtaining the geometry
Disk geometry parameters are specified in the options section of the
configuration file. Each disk parameter sub-section begins with
disk= disk_device, similar to the way how boot images are
specified.
It is suggested to group disk parameter sections together, preferably
at the beginning or the end of the options section.
For each disk, the following variables can be specified:
- bios= bios_device_code
- Is the number the BIOS uses
to refer to that device. Normally, it's 0x80 for the first hard
disk and 0x81 for the second hard disk. Note that hexadecimal
numbers have to begin with ``0x''. If bios is omitted,
LILO tries to ``guess'' that number.
- sectors= sectors
- and
- heads= heads
- specify the number of sectors per
track and the number of heads, i.e. the number of tracks per
cylinder. Both parameters have to be either specified together or
they have to be entirely omitted. If omitted, LILO tries to obtain
that geometry information from the kernel.
- cylinders= cylinders
- Specifies the number of cylinders.
This value is only used for sanity checks. If cylinders is omitted,
LILO uses the information obtained from the kernel if geometry
information had to be requested in order to determine some other
parameter. Otherwise,
it just
assumes the number of cylinders to be 1024, which is the cylinder limit
imposed by the BIOS.
Additionally, partition sub-sub-sections can be added with
partition= partition_device. Each partition section can
contain only one variable:
- start= partition_offset
- Specifies the zero-based
number of the start sector of that partition. The whole disk always
has a partition offset of zero. The partition offset is only necessary
when using devices for which the kernel does not provide that
information, e.g. CD-ROMs.
Example:
disk = /dev/sda
bios = 0x80
sectors = 32
heads = 64
cylinders = 632
partition = /dev/sda1
start = 2048
partition = /dev/sda2
start = 204800
partition = /dev/sda3
start = 500000
partition = /dev/sda4
start = 900000
Because many SCSI controllers don't support more than 1 GB when using
the BIOS interface, LILO can't access files that are located beyond the
1 GB limit of large SCSI disks on such controllers and reports errors in
these cases.
Next: Disk parameter table
Up: Disk geometry
Previous: Obtaining the geometry
Ross Biro
Sat May 20 13:51:22 PDT 1995