Add an entry for Fedora 8 to Grub

Q Under my vanilla Fedora Core 5 installation, the new Fedora 8 installation shows up as two partitions: /dev/hda7 and 8 under both fdisk and /dev, with none of the /dev/VolumeXX/GroupXX stuff I've been finding described on the net. I'd like to add an entry for Fedora 8 to my grub. conf file so I can boot it. I have been using Fedora Core 5 happily for a while, and it contains all my customisations and data.

A Fedora Core 5 and Fedora 8 use a similar LVM setup, and this is the source of your problem. Both distros name the first volume group VolGroup00. LVM uses names to distinguish between volume groups, and it cannot cope with two groups having the same name. As a result, it ignores the second one, which is why you cannot see its contents. The solution is to rename one of the groups, but you cannot rename the Core 5 group, because that is in use, and you cannot rename the other one, because the system cannot see it until the name is changed. The best way around this is to boot from a recent Live CD distro like Knoppix to give unfettered access to the volume groups. When Knoppix boots, open a terminal and run su (no password needed) to become root. Later versions of the LVM tools can identify different volume groups with the same name. Run vgdisplay and you'll see two groups both called VolGroup00, each with a different UUID. You can probably tell which volume group belongs to which disk from the sizes, so rename the Fedora 8 group with

vgrename xxxxxxxxxx Fedora8

replacing xxxxxxxxxx with the UUID from vgdisplay. You could now reboot into Core 5 and see both sets of logical volumes, although you will need to edit /etc/fstab on the Fedora 8 root filesystem to match the new name. You would still have a problem if you added another Fedora disk later, so it is best to rename both volumes now. If you do this, you will need to make some changes to boot with the changed name. First edit the boot menu with

mount /dev/hda7
joe /media/hda7/grub/menu.lst

to mount the boot partition and load the menu into an editor. Change the VolGroup00 reference and press Ctrl+K X to save and exit. Now mount the root filesystem and edit /etc/fstab with

vgchange -a y
mkdir /media/root
mount /dev/FC5/LogVol00 /media/root
joe /media/root/etc/fstab

The first line activates the renamed volume groups. Change the two instances of VolGroup00 to FC5, or whatever you named the volume group. Press Ctrl+K X to save and reboot. Of course, if you were feeling particularly lazy, you could reinstall Fedora 8 and set a different volume group name during installation. Now that you have non-conflicting volume groups, you can add an entry to Core 5's boot menu to pass control to the Fedora 8 menu.

title Fedora 8
root (hd1,4)
chainloader +1

will pass control to the bootloader on /dev/hdb5. I would also recommend setting up a separate home partition, so that future upgrades will be possible without losing your personal data and settings.

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