I shall just give a bit of background information. I updated a broken Ubuntu installation to Oneiric from the live CD a while ago, and everything appeared to be working fine. Because I don't use the affected PC (it's mainly for my family), I booted it back into Windows after trying out 11.10. However, during the upgrade, I checked the "install bootloader" option for some reason, even though GRUB was already installed. Before the upgrade, I had configured the system startup to load the Windows bootloader first, which would display the options "Microsoft Windows" and "Ubuntu". Choosing "Ubuntu" would obviously load GRUB, which would show all of the installed Linux distributions as well as an option to reload the Windows loader, located at the bottom of the list. However, after I upgraded, GRUB was default due to the reinstall. This wasn't a major problem, as I could always set the Windows BL as default, or just set GRUB to highlight the Windows loader option by default.
Anyway, to the real issue: at boot, the system drops to a GRUB rescue TTY, giving the error "unknown filesystem". Because I saw a shell that I'm not really familiar with, I typed some common Unix commands to see what kind of environment I was in. My first command was
ls, and it worked; it showed a list of filesystems. It output:
(hd0) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1).
I'm not sure what to do from here. I'm assuming I should boot into a live environment and do some common disk operations. Should I run
fsck? If all is well or repairs succeed, should I update the GRUB configuration? How so? If all is not well, what then?
Thanks in advance.