[lug] grub syntax RAID/SCSI/IDE mixed

D. Stimits stimits at comcast.net
Fri Nov 19 16:19:51 MST 2004

A long time ago before XFS was in the kernel tree, I installed on root 
partition via installing to ext3 first on a spare IDE drive, then using 
cpio to mirror it over to an XFS drive once I'd rebuilt the patched 
kernel to use XFS. Then I used a combination of chroot and lilo to set 
the MBR up (note that on this system with mixed IDE and SCSI I could 
simply tell the BIOS to boot from IDE or SCSI and either the original 
ext3 version or the SCSI version on XFS would boot). Unfortunately, I'm 
finding problems decoding grub syntax. My running version is on IDE 
drive with /boot/ on /dev/hda1, and / on /dev/hda2.

In building up the mirrored SCSI version, I cpio'd the /boot/ to 
/dev/sda5 (the first partition since it is the logical within the 
extended and there is no primary), and also cpio'd the rest over to 
/dev/md0. I now have a full mirror on /dev/md0/ if I also mount 
/dev/sda5 onto the boot subdirectory of the md0 mount point. Now I need 
to figure out two things, first of all the grub syntax and grub changes 
needed to make /dev/sda5 the boot partition, and /dev/md0 the root 
partition (note that the kernel has md support compiled in). I have not 
been using labels, for one reason I don't want to know how to set this 
up without labels. If the BIOS is set to boot scsi first, /dev/sda5 I 
think would be hd(0,0), but I suppose it could be hd(0,1) since it is 
inside of an extended. Which device syntax is the md0? I'm having 
problems with grub-install and it looks like it is because I don't 
understand grub well enough when mixing IDE/SCSI/MD.

D. Stimits, stimits AT comcast DOT net

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