Re: Breaking out of menu on "live disk", repairing grub

[Felix Miata]

On 2013-03-26 14:33 (GMT) Simon Hobson composed:

> OK, got my system running, but ...

> I could not get a working boot by chroot, update-grub, and update-initramfs. All my 
> attempts left me with "couldn't mount root, dropping to shell". Basically, soft 
> raid wasn't getting started, so the roof filesystem wasn't available. I hadn't tried it 
> before, but starting raid and then hitting ctrl-D to exit the shell resuted in the system 
> completing it's boot.
> After booting this way, updating the grub config and initramfs gave me a 
> working setup - I'm thinking it was more likely a problem with the initramfs 
> than Grub.

> So something else new I've learned :)

Mon, 25 Mar 2013 8:08:19 +0000 you wrote in part:

        The specific case is where I've copied all the files to a new machine 
or disk

My guess is the trouble you had may have stemmed from use of UUIDs in Grub 
stanzas and/or initrds. If you prepped the new disk prior to restoration of 
files rather than restoring via a partition cloning process, UUIDs would have 
changed, meaning root= would need to be different on the cmdline(s) on the 
new disk, and likely for fstab entries as well. "couldn't mount root 
filesystem" is a common giveaway that root= is wrong.

I use volume labels for root= and fstab, which avoids the UUID change 
problem, but suffers from the same duplication problem as when having cloned 
and then rebooting without removing the source first, leaving identical twins 
to confuse the kernel and init.
--
"The wise are known for their understanding, and pleasant
words are persuasive." Proverbs 16:21 (New Living Translation)

 Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata  ***  http://fm.no-ip.com/