I have two partitions for Linux systems (besides /home, swap and Windows 10’ partititions) using GPT on a big disk with Win10 preinstalled (and shrinked its partition).
I installed Lubuntu on (hd0,5) without problems, and GRUB is in /dev/sda1 (I suppose) because /dev/sda1 is an EFI partition.
My problem is that I can install a second distro on (hd0,6) but cannot boot into it. How do I insert a second distro into my GRUB file?
I do not want to erase my original GRUB because an entry for System Setup is included, and that is important for me.
Once I finish the installation process, and depending on which distro is, GRUB is installed in /dev/sda1 or /dev/sda (as the distro installation process reports). So I thought to edit the GRUB config file in distro 1 (/dev/sda5), but it doesn’t work. In one of my many tries, I corrupted the booting so I had to use boot/repair to fix it.
Here comes my second problem: now I have many files in /boot/efi and I do not know what should I keep and what to dispose. What should be in this directory?
Here is my partition table, just in case:
sda1 | FAT32 EFI SYSTEM_DRV (boot,esp flags)
sda2 | ? msftres
sda3 | NTFS Windows10 msftdata
sda4 | NTFS WINRE_DRV hidden,diag
sda5 | ext4 Lubuntu system
sda6 | ext4 Other Linux
sda7 | ext4 /home
sda8 | swap