Grub command line opening when selecting Ubuntu

Question

I installed Ubuntu using Wubi. Everything was working file when yesterday, I opened the Update Center and installed all the necessary updates. Now when I restart my machine and it prompts the dual boot option. Selecting Ubuntu now, opens a Grub command line window and the prompt waits to type-in any command. Ubuntu is not starting automatically.

What happened to the auto-load?

Solution

99% sure that the problem is with a Kernel update. Basically you installed a new brain to ubuntu but the update process forgot to tell the body to connect to it! :-/

If this applies to you, there is bug report on launchpad. Bug comment #3 and #7 seem to contain a workaround for manually booting the old version of the kernel.

I would add - to that thread - that if you manage to boot ubuntu with the old kernel, you could try to issue the command

sudo update-grub2

which should find out the new kernel and rebuild the normal Grub menu.

EDIT You should really visit the launchpad bug to check out if progress being made and new (hopefully easier workarounds), however, as of 27/11/09 16.25 GMT the following is the most complete solution provided there.

At the grub prompt enter:

linux /boot/vmlinuz-2.6.31-14-generic root=/dev/sda1 loop=/ubuntu/disks/root.disk ro quiet splash

initrd /boot/initrd.img-2.6.31-14-generic

boot

(if it doesn't work, change sda1 to sda2 or sda3 or ..., and please don't load kernel ...-15-...!)

Comments

[user1495803]

How to load the old kernel? And also what is the default name of Ubuntu kernel?

[mac]

@Rohit - Follow the link to the bug report, look at comment number 3.

[Jeremy French]

mac could you put the commands from that post into the answer. I was going to edit your post but don't have enough rep here.

[mac]

@Jeremy - (1) Did this answer fixed for you (I just saw your comment under the question). (2) I included the code to boot the image in the answer. I still think is a not-so-good idea though to crystallize here a solution that is likely to be improved in a matter of hours on launchpad (the code I pasted there, for example, is from just 3 hours ago...)

[Jeremy French]

@mac, yes this is what fixed it for me. even though there isn't a permanent fix (other than leaving the PC on). Thanks for posting the code.

[Admin]

this fix no longer works and the same issue was experienced here...complete reinstall needed.