Appendix E. An Introduction to Disk Partitions

117

may reside in the root partition (

/

). In either case, the partition in which

/boot

resides must conform

to the following guidelines if you are going to use GRUB or LILO to boot your Red Hat Linux system:

On First Two IDE Drives

If you have 2 IDE (or EIDE) drives,

/boot

must be located on one of them. Note that this two 

drive limit also includes any IDE CD ROM drives on your primary IDE controller. So, if you

have one IDE hard drive, and one IDE CD ROM on your primary controller,

/boot

must be

located on the first hard drive only, even if you have other hard drives on your secondary IDE

controller.

On First IDE or First SCSI Drive

If you have one IDE (or EIDE) drive and one or more SCSI drives,

/boot

must be located either

on the IDE drive or the SCSI drive at ID 0. No other SCSI IDs will work.

On First Two SCSI Drives

If you have only SCSI hard drives,

/boot

must be located on a drive at ID 0 or ID 1. No other

SCSI IDs will work.

Partition Completely Below Cylinder 1023

No matter which of the above configurations apply, the partition that holds

/boot

must be located

entirely below cylinder 1023. If the partition holding

/boot

straddles cylinder 1023, you may

face a situation where GRUB and LILO will work initially (because all the necessary information

is below cylinder 1023) but will fail if a new kernel is to be loaded and that kernel resides above

cylinder 1023.

As mentioned earlier, it is possible that some of the newer BIOSes may permit GRUB and LILO to

work with configurations that do not meet these guidelines. Likewise, some of GRUB and LILO's

more esoteric features may be used to get a Linux system started, even if the configuration does not

meet our guidelines. However, due to the number of variables involved, Red Hat cannot support such

efforts.

Note

Disk Druid, as well as automatic partitioning, takes these BIOS related limitations into account.