After installing Linux Debian on external HDD (not live Boot), is no booting possible. If I start the PC it automaticly jumps in grub-rescue. How should I fix it? On the Internal HDD is just Windows 10 installed.
Thank you for your Help.
If you were able to boot Ubuntu in the past, but not now, follow these steps to solve the problem.
ls command and Press Enter to see all the available
partitions. The entries will be shown as
(hd0,msdos1) (hd0,msdos2) (hd0,msdos5) etc.
Then type ls
(hd0,msdos1)/ to see the content of the drive. if you
see entries like
initrd, it is your Linux partition. If you
fail with (hd0,msdos1), try with (hd0,msdos2) and so on, until you
recognize your Ubuntu partition.
When you correctly identify your Ubuntu partition, type
root=(hdX,msdosX) , replace the
X with correct identified number. For
example, if you see
initrd entries by entering
(hd0,msdos5), the command will be
configfile /boot/grub/grub.cfg and type Enter. This will
bring you Previous Ubuntu grub menu.
Then choose the entry to boot Ubuntu.
After you booted up, Open a terminal and type sudo update-grub and press Enter. This will update the grub menu and prevent future problems.
In the case that you are not able to boot to Ubuntu after installation, re-installing Ubuntu is the best option. You can check this question: