Re: [gentoo-user] Duel boot - How to verify boot loader updates?

[Michael]

On Thursday, 8 December 2022 20:55:30 GMT Mark Knecht wrote:
> Hi,
>    This is a bit of a conceptual question, simplified but based on a
> machine I do own, from someone who knows very little about boot loader
> implementations. (I.e. - me) Thanks in advance for any pointers you can
> provide.
>
>    Assume a machine with two separate M.2 SSDs. The M.2 devices are
> identical in size and from the same manufacturer. For the sake of
> discussion they are partitioned identically and they both have the same
> distro installed. One is stable, the other is bleeding edge. For simplicity
> there are no other disk drives involved in either installation. Both
> installs have the same boot loader, grub2 I guess, and both have
> configurations that boot themselves by default but offer the other drive as
> a second option.
>
>    Assume the bleeding edge system (or the other - it doesn't matter to me)
> gets a grub2 update, and further assume the update is either automatic or
> done by someone other than yourself. Whoever did the updates 'tests' the
> machine by booting into both versions, and both versions are tested as
> default in BIOS so that no matter what everything appears to be working.
>
>    THE QUESTION: After the fact, if I wanted to look at the two
> installations in detail, how would I determine that the grub update was
> done to the installation doing the update and not done to the other
> (nearly) identical installation?
>
> Thanks in advance,
> Mark

Once booted into one of the OSs you could run something like 'eix -l grub' or 
'emerge --search grub' to see which version has been installed.  I don't 
recall there being a GRUB filesystem specific pointer as to what version it is 
when just looking at the installed GRUB files.

To check the GRUB version of the second OS without booting into it, you can 
grep for grub in its /var/log/emerge.log