[conspire] upgrade and grub

[Rick Moen]

Quoting Paul Zander (paulz at ieee.org):

> So I decided to try my laptop instead.  This would be the machine that was at CABAL a couple years back.  Because of the factory  installed win 8, the least difficult way to run "multi-boot" was to get an external USB drive for debian and leave the internal drive for win.
> 
> sources.list as previously discussed.  All went reasonably well until I get to an issue about grub.
> First dialog box:The GRUB boot loader was previously installed to a disk that is no longer present or whose unique identifier has changed for some reason.It is important to make sure that the installed GRUB core image stays in sync with the GRUB modules and grub.cfg.    
> 
> There is a dialog box with choices: [ ] /dev/sda (1000204 MB; Toshiba ...                # that is the drive with windows [ ] /dev/sdb (1000204 MB; Storage Device) [ ]  - /dev/sdb1 (209715 MB ; / )                        # the root partion
> All I can do is move the cursor between the three sets of [ ].   I tried to select the second or third choice, but the next dialog box warns me that I am not installing grub anywhere and do I really want to do that?
> I did a little sleuthing in a different window.  grub.cfg is in /boot/grub/gparted tells me that /dev/sdb1 has the boot flag set.
> Maybe my only issue is figuring out the dialog box.  

I hope someone with more relevant experience will speak up and help.
As a necessary disclaimer:

1.  I really don't like GRUB at all.
2.  I carefully avoid multi-OS booting and complex boot setups.
    (IMO, it's a lot smarter to meet any multi-OS needs using
    virtual machine technology, though there are edge cases where
    this isn't attractive.)
3.  I am not good at solving GRUB problems, for lack of experience.

My prejudices, and in particular item #2, tend to keep me out of trouble
and avert the need to solve bizarre GRUB problems.


That having been said:

It would have been really handy, about now, if you knew _where_ you 
installed GRUB when you last did so.  It could have been operating from
the master boot record of some primary boot device.  Or it could have 
been reached from whatever bootloader _was_ in that place, via
chainloading it.

It would also be handy, about now, to know which physical drive is set
in your BIOS (or EFT thingie, or whatever) as the default boot device.
Or maybe you mean that you pick 'external USB drive' from the POST-time
boot menu, so that the hardware branches immediately to whatever's in
the MBR on /dev/sdb, which I take to be your USB-connected 'Storage
Device' described by the GRUB update routine.

I'm going to chance a Silly Wild-Assed Guess (SWAG) that you should pick
the second checkbox, /dev/sdb -- the MBR of that drive device.

If this fails, then you might find yourself doing sudden urgent GRUB
repair.  Personally, I would aim to do that from a live-CD Linux
distribution familiar to you, rather than from, e.g., a GRUB>
maintenance prompt on a partially broken system.


At this point, I'm going to stand back, and hope someone with more
relevant experience steps in.