[ILUG] harddisk swap

Paul Jakma paul at clubi.ie
Fri Apr 30 11:27:57 IST 2004


On Fri, 30 Apr 2004 P at draigBrady.com wrote:

> The fact is that for grub the MBR is disk agnostic.

Is it? AIUI, the grub MBR has the location on disk of the stage-1.5
fs loader hard coded into it (just as the lilo second stage
(chain.b?) in the bootblock had the location of the kernel image hard
coded into it).

> Personally I build up a disk image in a file which can be copied
> onto IDE/SCSI/CF disks.

Including MBR, right? The location of the 1.5 stage to the MBR is
constant, however, the C/H/S could vary between disks surely? Perhaps
grub is cleverer about translating its offset-to-stage-1.5 to C/H/S
than lilo¹ is, but I'm reasonably certain changing C/H/S would break
lilo boots. (cant remember for sure though. It _definitely_ breaks
the Windows NT second stage bootloader though).

1. LILO usually stores C/H/S, unless linear is specified iirc. Which
obviously would break if geometry changes.

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
	warning: do not ever send email to spam at dishone.st
Fortune:
"... the Mayo Clinic, named after its founder, Dr. Ted Clinic ..."
		-- Dave Barry



More information about the ILUG mailing list