Boot process related logs. What? Where?

[Richard Owlett <rowlett@cloud85.net>]

My explicit question is:
   Does an annotated list of boot process related log files and
   their locations exist?

I did a reasonably typical install from DVD-1 of Debian 9.1.0 .
It is at least partly functional - I can log in as root.
The only error message during boot was that it could not find a device 
with a specific UUID. It didn't stick around long enough to manually 
copy the string.

What is odd is that the last 5 characters match the UUID of the 
partition it is booting from.
I need to know:
  1. the complete UUID string
  2. what was it looking for at the time

I know that many log files are under  /var/log/ .
I used an operable system to examine the files on the failed partition 
and could not find a useful readable file. One file had an interesting 
name, but was apparently a binary file.