I've decided recently to install Ubuntu on an external SSD. I want to use it as a "work OS" that I could plug anywhere.
After some research, I found that with usb 3.0 throughput, there are no problems running an OS from an external drive.
I have also found this recent guide to install a portable ubuntu on an external drive.
I've managed to install ubuntu 20.04 (rather than 19.10 in his tutorial) which works quite well but is bound to the computer where I installed it.
So in order to manage this issue, while being on a "Try ubuntu" thumb drive session, they describe how to mount the external device with the fresh ubuntu install, to change the mount points in /mnt/etc/fstab and to chroot in it for installing grub on the efs partition. (If you wanna check, part E of his guide)
The problem is that I have followed each steps carefully 3 times, but when I boot on this device with another computer that only has a W10 on it, my screen freezes with this error: error: file ./boot' not found. I have checked on my SSD and the /boot/* directory does exist.
The message on my screen when I boot on the external SSD
I have tried different arguments with grub-install but nothing seems to change.
Do you have any ideas as to why another computer couldn't find the grub installation on my SSD?
