When calling "update-grub" it creates a grub.cfg that is aprox. 0,5 Mb large.

The most of the entrys seems to be invalid. This causes a unwanted timeout when starting the computer. For many seconds there is a black-screen before the grub-bootmenu is shown.

The entries look like this:
/dev/sda1      ext4	-> Debian 9.2 (update-grub is called here)
/dev/sda4      ext4	-> Debian 9.2
/dev/sda7      ext4	-> Debian 8.7

When calling "update-grub" on the other two Debian-installations, I got a similar behaviour. The MBR is currently written by the OS on "/dev/sda1" through "grub-install".

This bug is related to a previous created Installation-Report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=879514
Debian Release: 9.2
500 stable-updates ftp.tu-chemnitz.de
500 stable security.debian.org
500 stable ftp2.de.debian.org
--- Package information. ---
Depends (Version) | Installed
===============================================-+-=========================
grub-common (= 2.02~beta3-5) | 2.02~beta3-5
dpkg (>= 1.15.4) | 1.18.24
OR install-info |
libc6 (>= 2.14) |
libdevmapper1.02.1 (>= 2:1.02.36) |
liblzma5 (>= 5.1.1alpha+20120614) |


Package's Recommends field is empty.

Package's Suggests field is empty.

For more Information I attached a complete grub.cfg file.

It seems that this problem is caused by the script /etc/grub.d/30_os-prober that I doesn't touched.


Furthermore my other PC with Debian 8.7 and Debian 9.2 installed also have this buggy grub.cfg but is is only aprox. 20kb large and have entrys like the following:

As expected there is no big waittime at the start of the grub-bootmenu on my other PC.


As a conclution I expect that with more than one Debian installed it results in that behaviour and gets noticable with 3 or more.