My drive situation: 3 drives
A.)Original os on drive 1 was windows
B.)Then EOS on drive 2 was installed - no problem - grub lets me choose EOS or Windows
C.)Then another EOS install (testing purposes) on drive 3 - os-prober/grub can’t detect this system, but I can boot that system using boot menu. Os-prober/grub on this disk can’t detect the original EOS install, but can detect Windows (so it is exactly the same situation as with the firt EOS install).
But I am able to mount the partition from other EOS, so I can see them when inside the system.
Well, I don’t really need that secondary install to be btrfs. Lets say I install it as ext4, while keeping my primary install as btrfs.
Should it work normally, if I try to os-probe and update the grub menu from that primary system? Do I need to create that EFI partition on that drive with secondary EOS install (I do have right now)?
The answer is yes.
I reinstalled my secondary EOS system (and added couple more on top of that) using ext4 and os-probe from my primary system works as expected.
Thank you for your time