Upgrade to 11.04 failed, how do I repair when it won't even boot?

Question

I am new to Ubuntu but really enjoy it. A couple days ago I was prompted to upgrade to 11.04, or whichever is the newest version. I think I had 10.10 before. Something happened overnight while installing and when I turned my computer on this morning the screen looked crazy. I reset the computer and now I just get the Ubuntu splash screen but nothing seems to be happening.

I am able to launch from a CD, and it sees my hard drive and all my files, but I don't want to have to wipe the hard drive and start all over again. I even tried backing up some of my files while booting from my CD, but there is an X mark on some of the files saying I don't have privileges to access them.

I am not sure what to do. Any ideas?

Answer 1

Right after your bios spalsh press shift that will show your bootloader menu called grub menu which will have something like this listed.

Ubuntu, with Linux 2.6.38-10-generic
Ubuntu, with Linux 2.6.38-10-generic(Recovery Mode) 

Try recovery mode and see what errors you get during the boot process Or

press e during grub listing and replace quiet splash with text where you see it. Basically some screenshots with further information on bootloader can be found here. If you have some filesystem errors you may check your filesystem from live-usb or gparted/Disk-Utility from live-usb.

P.S. If you don't mind resetting the configurations, I think using new install is less tedious than recovering. Having said that if you have different home partition, your old settings can be used as well after you install the application for the settings that is. You should recover/backup your important data as @Philippe recommends.

Answer 2

First thing to do is make a backup of your files (if you don't have that already!). Probably the best is to boot from a LiveCD

But if I understand you correctly, the system won't access them. To solve that you could try to access them as root.

 sudo cp /mountpoint/oldfiles /media/usb_or_whatever

Eventually chroot into your old drive is that would not work directly.

Then I would recommend a complete re-install. I had this before also. Ubuntu (was) not really able to make upgrades. (Although now it seems to be supported as it appears on the update manger---I believe from 10.10 onwards).

But more importantly. Next time backup FIRST!!!