Problem: I have installed two Ubuntu servers, 10.04 32-bit and 10.10 64-bit, in a multi-boot environment (also have FDOS and WinXPsp3). The 64-bit will not boot because grub can't find the UUID for the disk with the 64-bit system.

Brief Background:

• Installed 10.04 LTS two months ago with no problems. 10.04 is in a primary partition on hda with FDOS.

• Installed 10.10 (64-bit) in a new primary partition on the same hd. The install seemed to go ok, but the MBR and the fs on the 10.04 were corrupted; could not boot. Restored drive, and rebuilt grub.

• Installed 10.10 on separate hd (hdb). In grub step all OS's were recognized so I pointed the grub to hda. Grub failed to boot.

• Rebuilt grub from 10.04 on hda. All systems recognized but 10.10 will not boot because it says it cannot locate the UUID specified.

• Compared the grub.cfg for both systems, the UUID specified for hdb is the same. Also, when I mount the drive for 10.10 on the 10.04 system the drive UUID is consistent.

I know I must be missing some thing, but I know not what. Have searched and can't find any clues. All other OS's boot ok.

Hardware: AMD64 4GB, 2 internal IDE drives (hda and hdb), 1 internal SATA (hdc WinXP), various USB and Firewire Drives (no bootable systems).

Anyone have any ideas what might cause the problem?

Thanx in advance for any thoughts on this.

Check /dev/disk/by-uuid and double check the uuid is entered correctly.

If you can see all os'es you can use whichever os that boots then select diskthat is not booting,
go to "/usr/share/applications/terminal" in file system folder
try
"sudo os-prober"
"sudo update-grub"

According GPARTED disk info, this is the correct UUID, and as you are aware Grub pulls the info from the sysinfo ... so, no joy there


All other OS's boot ... and the prober runs automatically with update -grub ... this was redone with the same results.

UPDATE
Having time available, I reinstalled 10.10 and pointed the Grub to the MBR on the actual disk (hdb), and updated grub on the 10.04 disk (hda) - interesting results:

UUID changed (of course) to 86626f7-691c-4545-b656-f882edeb07d2
When pointing BIOS to boot from hdb it failed in Grub (no screen - grub error) because it was unable to find UUID from previous install (915ca52c-6740-4758-b216-1709b26c8cea).
When doing normal boot from hda all OS's are bootable except 10.10, and it failed as in the original, only unable to find the new UUID - curioser and curioser

Think I'll have to go into Win (ugh!) and check the mbr sectors (haven't found the right tools in Ubuntu yet).

Anyway thanks for the input guys - any other ides will be gratefully accepted.

The os that will not boot:

Try this
Boot the Ubuntu that wiil boot
Ubuntu can mount the other os.
If the other os is sda7 mount from within bootable system.
If you have seperate /usr/ partition mount it,
go to /usr/share/applications/terminal "double click on icon"
run sudo os-prober
"sudo update-grub"

Since that one is the os you can't get running from your grub it'll be recognized first.

Thanks again for the ideas my friends.

I have installed 64-bit in a GPT, and can now boot it. Eddy - I tried you suggestion w/o success. I believe it may have to do with Grub differences - I was unaware of Grub2 - installed in the "primary" 32-bit but it made no difference (same errors); but now can boot from the GPT and all systems are accessible. Problem isn't "solved", but is circumvented. I have some ideas, and will play with them as time permits, but until then please consider the question closed.

Many, many thanks,

The Bear

I had the same problem, thanks friends.