Dual booting with GRUB makes HD disappear
 

Hi all

THis is my first post, apologies if this has been covered elsewhere - I can't find any reference to it.

OK, I've just installed the latest download of RedHat, and am using GRUB to have the option of dual booting between LINUX and Windows XP. My problem is that when I choose XP, my second hard drive is not visible after it has loaded.

My current setup is that my first hard drive contains all my music in a single partition. My second hard drive contains two partitions, one containing XP, the other Linux. My GRUB boot options to boot XP are as follows:

map (hd0, hd1)
map (hd1, hd0)
unhide (hd0,1)
hide (hd0,0)
rootnoverify (hd0,0)
chainloader +1
makeactive
boot

when XP loads, C: is visible, but no other partitions - not my LINUX partition, not my music drive.

I've tried various combinations of unhides and hides, none of which seem to work, though as I'm not au fait with the GRUB syntax I admit I could be doing something wrong.

Is it GRUB that is preventing XP from seeing my music drive? should I switch drives so the XP/Linux drive is first?

Any help gratefully received, thanks.

don't worry about hiding them, remove all the hide/unhide and change the partitions back to visible.
XP can't see Linux partitions, if you music drive is a fat32/ntfs, go in disk manager and try giving it a drive letter.

OK, I removed all the hide/unhide gubbins and Windows still boots okay, so that's a help. However, the Music drive is still invisible. Disk Manager thinks the drive is NTFS, however PartitionMagic thinks the drive is 'CP/M, Sys V'. This is very strange. I've never head of this type, has anyone else?

If anyone has any ideas, let me know. I appreciate this is becoming slightly OT, but I'm posting it here in case it is GRUB that's causing me problems.

thanks!

do a "fdisk -l", whats the partition type on that music partition?

hey

wow, being such a linux newbie i'm even having troubles getting fdisk to run. I go into Linux, open a terminal and type fdisk, but no luck - it doesn't recognise the command. Do I need do open fdisk from a boot disk?

sorry for such an embarrasingly newbie question :-/

try "/sbin/fdisk -l" as root

very bizarre. fdisk lists dev/hda as having a CP/M file system. Do you recognise this? I'm at a loss as to how it was converted, it was either through PartitionMagic or in the LINUX install process. I'll try to work something out at this end. Hopefully I haven't lost the best part of 30Gb mp3s...

ha! problem solved. i used Disk Manager in Windows to convert the drive to a Dynamic drive. After that Windows had no problem assigning a frive letter. The odd thing is that all the way through, Disk Manager was convinved the volume was NTFS.

anyway DB, thanks for your help, it's much appreciated.

It's just the partition id in the MBR, and can be safely changed if you know what you're doing.
What hiding a partition does it that it changes the partition to a certain id, though I'm not exactly sure why grub(or partition magic) didn't use type 17(Hidden NTFS/HPFS)
Just change it to what its suppose to be, which is type 7(HPFS/NTFS)

Yea that would work too, IIRC a dynamic disk uses 8 megs of space somewhere on the partition instead of the MBR to store the partition table, therefore you basically got around the partition id problem.

cheers, i'm going to try that anyway, it will give me valuable experience. thanks for all your help :-)

Not exactly sure if GNU fdisk supports dynamic disks (Linux kernel does)
If its working right now don't worry about it.