The glitch, which I documented in my other Grub thread, using the statement "Grub sees only my new LFS build and not my other stuff," really has relevance for only those who want a multi-boot system. I have one. Although I manually entered a grub.cfg entry for that "other popular (?) operating system," I was frustrated that grub-mkconfig didn't behave like I've seen it in Ubuntu.

The path to investigate took me to this statement in the Grub manual:

"'GRUB_DISABLE_OS_PROBER'
Normally, grub-mkconfig will try to use the external *_os-prober program, if
installed,_* to discover other operating systems installed on the same system and
generate appropriate menu entries for them."  [The emphasis is mine.]

Closer inspection of /etc/grub.d/30_os-prober revealed:

if [ -z "`which os-prober 2> /dev/null`" -o -z "`which linux-boot-prober 2> /dev/null`" ] ; then
  # missing os-prober and/or linux-boot-prober
  adjust_timeout
  exit 0
fi

OSPROBED="`os-prober | tr ' ' '^' | paste -s -d ' '`"
if [ -z "${OSPROBED}" ] ; then
  # empty os-prober output, nothing doing
  adjust_timeout
  exit 0
fi
This script will "bail out" with no output other than "Begin...End," if os-prober is not installed or doesn't do anything. This is what led me to believe that Grub was operating incorrectly.

I discovered using 'find' that os-prober was not on my LFS build, but that it was in Ubuntu. Although referenced in the manual and "called" in the script, it is not a Gnu or Grub thing. It came from the Debian installer and there is a discussion and the ability to download it at this location <http://joey.kitenet.net/code/os-prober/>

I don't have a report on success or failure on using this in LFS yet. There is no install target in the makefile and the documentation makes the install non-intuitive. I'm using my Ubuntu as a guide and was brute forcing with 'mkdir' and 'cp,' when I realized that I need to brush up on how to use 'install.' It might make it easier.

os-prober also has a "linux-boot-prober" that will look across device boundaries for other linux distributions. I know that there are many different ways to get the menu entries and look for other distros to put in the grub menu. I'm lazy and just want grub-mkconfig to see everything.

If all goes well, maybe it's "write a hint" time.

Dan

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