I have Fedora Core 5 on my laptop dual boot with Windows XP. I want to have Ubuntu Dapper Drake as a secondary Linux distro.

When I installed Ubuntu, I created partition /VolGroup00/LogVol03 under the FC5 LVM manager and skipped the grub installation (because I didn't want Ubuntu's grub installation to mess up my FC5 operation). I'm now trying to add an Ubuntu boot to FC5's grub.conf, and having all kinds of problems.

I tried a large number of ways to get grub to find the Ubuntu kernel in /VolGroup00/LogVol03, or /dev/VolGroup00/LogVol03 or /dev/mapper/VolGroup00/LogVol03 or /dev/mapper/VolGroup00-LogVol03 and got all kinds of messages, generally related to grub error 17 (doesn't know file system, can't mount partition).

I finally hit on copying the Ubuntu kernel to /boot (along with the FC5 kernels) and trying to boot it from there. The Ubuntu kernel starts up but I've tried all kinds of ways to say root=something to get the Ubuntu kernel to find its root partition. One thing I tried (I forget what it was) got Ubuntu to recognize that there were 4 logical volumes but then it sat "waiting for the boot partition". Other things I've tried led to kernel panics. I also copied the initrd to /boot and tried various ways to get it to help.

I tried using root (hd0,2) (as for the FC5 booting) and root (hd0,4) as the first grub statement after title Ubuntu Linux. I think (hd0,4) is grub's notation for where the LVM is located. I looked using gparted and found an hda4 Extended which subsets to hda5 (unknown), which is the overall LVM partition.

I've read the grub documentation repeatedly to no avail. Grub doesn't seem to know about LVM, although it seems to work OK with it in FC5.

Can anyone give me ideas or hints on what to tell grub or the Ubuntu kernel to get Ubuntu to boot?

I'm having the same issue, did you ever get grub to boot up on the LVM?

I never got it to boot. I did follow the problem further and found that somehow the Ubuntu initial ram disk (initrd) functions are not recognizing the file system type of the root partition. If you wait after the error message, the ram disk gives you a shell prompt. I tried to manually mount the root partition then, and was able to do it by including -t ext3 in the mount command. However, I never could get the same effect by passing information through grub. It will probably require a new ram disk (initrd) configuration to do it.

There is a large thread on the Ubuntu forum on this issue and two bug reports in their system, one marked as high priority and confirmed.

We aren't alone in having the problem.

I finally got it to work, with the debootstrap method of installation.

The only thing I had to do different from the docs was -- the base package did not come with lvm2 so I had to install it and also copied over the kernel and initrd image file to the "/boot" mounted boot partition which is on a standard partition (non lvm).

Here are the details:

http://linuxweblog.com/node/361