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Thread ID: 41484 2004-01-12 21:45:00 RH9 & RH7 dual boot JohnD (509) Press F1
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207025 2004-01-12 21:45:00 I have just finished upgrading a school gateway & Samba server from RH7.0 to RH9. I used a new disk for RH9 and intend to dual boot with the old OS to allow for disaster recovery (hopefully will never need to). I have done similar before by copying the kernal of the secondary OS into the /boot directory of the primary one and altering lilo.conf.

In this case I have the RH9 disk as master on IDE0 and the RH7 disk as slave on IDE0. When I boot, the root partition is not mounted (a message about duplicate / partitions).

In thinking about this, I decided to remove lilo from the RH7 disk. (Not sure what else could have caused this). Rebooted with the same message. When the RH7 disk is disconnected, RH9 boots fine.

Not sure what is going on? Thanks for any ideas! 		JohnD (509)
207026 2004-01-13 01:39:00 What is going on? It's all perfectly logical . :D

RH7 mounts a disk partition with the label "/" on its "/" mount point . So does RH9 . Even if they are different partitions on different drives, they are both called "/" . How's the poor loader supposed to know which one you want? ?:)

I can suggest 2 ways around this . I'm pretty sure that both will work . B-)

1) use fdisk to change the labels of the partitions to "RH9" and "RH7", and change the image definition line in /boot/grub/grub . conf for the loader to read " . . . root=LABEL=RH9" and " . . . root=LABEL=RH7" . (this LABEL= is the format that grub defaults to) .

2) change the image definition line to " . . . root=/dev/hda5" and " . . . root=/dev/hdb5" . Changing this in grub works for me . :D (the device letter [a,b,c, ] and partition number [1,2,3,5,6, ] to suit, of course ;-))


It will pay to make matching changes (for consistency) in the two versions of /etc/fstab: I did this after booting my RH9 with the new grub . conf . . . I don't think that /etc/fstab is used in the boot process -- because it doesn't exist until the partition is mounted . :D)

I think this will work for lilo too . . . IF they have changed to use the LABEL= format rather than /dev/hdXy .

I had a different problem . . . after the first page or so of boot information it was failing to find the LABEL=/ disk and halting . BLEEAGH . I thought I'd lost the disk . But it had the kernel, etc . So out with the recue disk . . . and a bit of a play .

It doesn't matter what the partitions are labelled they are mounted on "/" and that's what the system knows . I hope . :D But I'm pretty sure you will be safe to use the /dev/hdXY method . It's the one I'd go for . 		Graham L (2)
207027 2004-01-13 01:39:00 What is going on? It's all perfectly logical . :D

RH7 mounts a disk partition with the label "/" on its "/" mount point . So does RH9 . Even if they are different partitions on different drives, they are both called "/" . How's the poor loader supposed to know which one you want? ?:)

I can suggest 2 ways around this . I'm pretty sure that both will work . B-)

1) use fdisk to change the labels of the partitions to "RH9" and "RH7", and change the image definition line in /boot/grub/grub . conf for the loader to read " . . . root=LABEL=RH9" and " . . . root=LABEL=RH7" . (this LABEL= is the format that grub defaults to) .

2) change the image definition line to " . . . root=/dev/hda5" and " . . . root=/dev/hdb5" . Changing this in grub works for me . :D (the device letter [a,b,c, ] and partition number [1,2,3,5,6, ] to suit, of course ;-))


It will pay to make matching changes (for consistency) in the two versions of /etc/fstab: I did this after booting my RH9 with the new grub . conf . . . I don't think that /etc/fstab is used in the boot process -- because it doesn't exist until the partition is mounted . :D)

I think this will work for lilo too . . . IF they have changed to use the LABEL= format rather than /dev/hdXy .

I had a different problem . . . after the first page or so of boot information it was failing to find the LABEL=/ disk and halting . BLEEAGH . I thought I'd lost the disk . But it had the kernel, etc . So out with the recue disk . . . and a bit of a play .

It doesn't matter what the partitions are labelled they are mounted on "/" and that's what the system knows . I hope . :D But I'm pretty sure you will be safe to use the /dev/hdXY method . It's the one I'd go for . 		Graham L (2)
207028 2004-01-13 07:28:00 Thanks Graham - will try out next time I am there.

JohnD 		JohnD (509)
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