Friday, June 17, 2011

Grub prompt after upgrade to ubuntu 11-04

I got bit by this when I upgraded "mini", my 11" acer to ubuntu 11.04. Rebooting left me at a grub prompt. The exercise has left me with an improved feel for the grub2 interface and boot prompt -- it's actually pretty slick with the TAB completion. Improved in-grub help would have been nifty, instead I found myself doing research on my phone.

Using information from aaron kelleys blog[1] and information available from tab completion I performed the following steps which led to a successful boot. After the root command, filename tab completion looks at that drive.

Boot from grub prompt:

root (hd0.5)
linux /vmlinuz root=/dev/sda ro
initrd /initrd.img

Alternative, equivalent boot from grub prompt:

linux (hd0,5)/vmlinuz root=/dev/sda ro
initrd (hd0,5)/initrd.img
After booting, these steps updated grub on the MBR for my root drive:
sudo grub-install /dev/sda
sudo update-grub

For a taste of the flip side, I restarted into windows for windows update. Looks like it's been 6 months since I booted windows7, so 300Meg to download. Question: Will it be finished or pwned when I get home tonight?



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