I did the following test : - install Ubuntu 10.04 on my dev/sda3 , it is correctly recognized by os-prober - move all its files into a folder (to simulate its deletion while being able to easily restore it) :
sudo mount /dev/sda3 /mnt ; sudo mkdir /mnt/test_delete; sudo mv /mnt/* /mnt/test_delete - Result : os-prober still detects it !
1) Is it an expected result ? 2) How can I hide an OS from os-prober (without deleting it) ?