Hello, during the installaton of a kali and buster system onto the same hard discs I ended with only one entry for either kali or buster in the grub boot menu, depending on what was last installed.
The problem is, that the grub installer scripts look for the specific file "os-release" which is located under /lib to find/identify other installations. Unfortunately, /lib is now just a link to /usr/lib in the "root (/)" partition. Before it was the directory ON the root partition. Therfore grub is not able to find other linux installations. One way out is to read the fstab file on each root parttion, mount the usr partition and read each os-release file. My partitioning of the HDs to /boot (Common for kali and buster) the / ( sda2 for Kali sda3 for buster) /usr ( sda(x) sda(y) /var dito /tmp dito /home dito Regards /Ralf Schneider
