how to tell where it booted from

[Tim]

Allegedly, on or about 15 February 2016, Mike Wright sent:
> I have several large disks filled with experiments and multiboots.  I 
> need to make changes to the current /boot/grub/grub.cfg but I have no 
> idea which one I'm using or which one of the systems' grub config
> tools were used so I don't dare just grab any old one and use it

I think the simplest way is to slightly customise each one, so you can
see differences in the text.  Then match what you see on-screen as you
boot, and the files you look at on the drive partitions.  Change the
text that's for you, without modifying anything that affects how booting
works.

Usually, with things like that, I'd look for the kernel version numbers
in the grub.conf file, but they don't use a single flat file, any more.

> Does the boot process leave any footprints behind telling where it 
> booted from?

I don't think there's an guarantee that what was GRUB's root (which
doesn't have to be a "/boot") at boot time remains mounted.

-- 
[tim at localhost ~]$ uname -rsvp
Linux 3.9.10-100.fc17.x86_64 #1 SMP Sun Jul 14 01:31:27 UTC 2013 x86_64

Boilerplate:  All mail to my mailbox is automatically deleted, there is
no point trying to privately email me, I only get to see the messages
posted to the mailing list.

Lucky for you I typed this, you'd never be able to read my handwriting.