Bug #38309

[Federico Tello Gentile]

This bug

http://savannah.gnu.org/bugs/?38309

Is actually a bug. Here's my attempt to find help on an unbootable system

http://askubuntu.com/questions/271898/what-is-grub-doing-while-it-takes-9-minutes-to-start-booting-the-kernel

The thing is grub.cfg was 11.6 MB. 175191 lines of menu entries 
generated by /etc/grub.d/30_os-prober

As grub was not showing anything except a blank screen forever, my 
guesses where faulty hard drive, faulty motherboard, broken RAID...

This was a 2009 Ubuntu installation that had been updated every 6 months 
to the newer release. The symptom started around 2013, (maybe after the 
Ubuntu guys pushed a grub upgrade?), grub was taking longer and longer 
to boot and running grub-update took long too on every kernel update. 
Until it was 9 minutes long and later more than 15 minutes and I gave up.

The damaged grub.cfg file is compressed here:
http://ubuntuone.com/78ofzJmQEn5ldlA7bZsQwy

I will be monitoring that file in my new installation so see if it grows.