[vox-tech] SOLVED - Re: Linux live disk's install attempt onto external drive botched my internal drive's grub!

[Bill Kendrick]

Ok, the solution was easy.  From the "grub rescue>" prompt, I had to
poke around to see what was what, and where.

My laptop's /boot partition was coming up as "(hd0,msdos1)",
and when I did an "ls (hd0,msdos1)", I saw things like:

  grub/
  memtest86+.bin
  ...
  vmlinuz-3.13.0-51-generic
  initrd.img-3.13.0-51-generic
  ...

So all I had to do at that point was tell grub how to boot:

  set root=(hd0,msdos1)
  set prefix=(hd0,msdos1)/grub
  insmod normal
  insmod linux
  linux (hd0,msdos1)/vmlinuz-3.13.0-51-generic
  initrd (hd0,msdos1)/initrd.img-3.13.0-51-generic
  boot

A bunch of kernel boot-up noise appeared, and I was prompted to enter
the passphrase to decrypt my root (/) directory, and after a moment,
my KDE login screen appeared!

I brought up a shell, and run "sudo grub-install /dev/sda"
(notice, not "/dev/sda1").

Rebooted, and here I am.  Whew!

Thanks very much to my coworkers (and sometimes LUGOD visitors)
Case & Dmitriy.

And also to my wife for putting both kids to bed while I panicked
in here ;)

-bill!


On Sat, Jul 16, 2016 at 12:36:46AM -0700, Bill Kendrick wrote:
> 
> So we got a new SSD drive for Melissa's laptop, and I've placed a Kubuntu
> installer/live demo image onto a USB flash drive.
> 
> Melissa was busy working on her laptop, so I decided to just
> get the install onto the new SSD, and we can physically migrate
> drives between her laptop at our leisure.
> 
> So, I booted _my_ laptop up with the installer USB flash drive, and
> stuck the target drive for the install (the SSD drive) into an
> external SATA enclosure, and connected that to my laptop via its USB cable.
> 
> Then I told the installer to install onto that external drive.
> 
> I answered a few questions, watched the enclosure's blue LED blink at me
> for 10 minutes while the installer did its job, and done!  "Great," I assume!
> I unplug the installer USB flash drive, and try to boot up the
> freshly-installed Linux off of the external drive enclosure.
> It didn't come up.  That's not good, but not a disaster.
> 
> But, it gets worse...
> 
> So I unplug the SATA enclosure's USB cable as well, and reboot my laptop again.
> Now I'm staring at a "grub rescue>" menu!  Nooo! :^(
> 
> Apparently, the installer slammed an update to GRUB(?) on my laptop's
> _internal drive!_  (Full disclosure, I know almost nothing about GRUB since
> I never need to deal with it.)  So now I can't boot my laptop!
> (Aaand, since it was handy, and is newer and faster than my personal drive,
> I was using my work laptop.  "Why should it matter," I assume,
> "I'm installing Linux onto an _external drive_.")
> 
> 
> I Googled around and discovered something called "boot-repair",
> which I installed onto the live/install USB flash drive, but when I ran
> it in it's default / recommended mode, it didn't seem to help me.
> 
> The results of its scan can be seen here:
> http://paste.ubuntu.com/19599532/
> 
> It seems like I got bit by this bug...?
> https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/384633
> 
> 
> I'm seeing a LOT of questions and answers about this kind of problem
> online, but a lot of it is old, a lot of it has to do with people
> who are trying to boot Linux off an external drive (not my goal;
> my goal was only to install it there; I guess it was foolish for me
> to assume that that's a "thing one can do").
> 
> I'm asking coworkers for assistance, but since many are remote,
> I figured I'd ask here, in case someone local feels like dropping by
> (or meeting me somewhere) to help fix this.
> 
> Thanks,
> 
> -- 
> -bill!
> Sent from my computer
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-- 
-bill!
Sent from my computer