I just booted CloneZilla from USB and cloned the NVMe disk to a 4TB HDD.
Then I booted from the HDD and everything seemed to be ok.
I noticed the NVMe was still be used for booting.
Bash
$ mount | grep boot
/dev/nvme0n1p1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
So I removed the NVMe to check if the HDD would still boot on its own.
It does. Great.
But after reinstalling the NVMe I cannot from it.
Code
Reboot and Select proper Boot device
or Insert Boot Media in selected Boot device and press a key
I can still boot from HDD.
I guess booting from HDD after cloning did overwrite something in /dev/nvme0n1p1.
But what? How can I fix this?
And how can I prevent this "deconstructive behaviour" in the future?
I guess I have to edit the Grub config after cloning it from the NVMe?!
My goal is to clone/copy/rsync the content of the system partition to the HDD for redundancy.
btw: Still experimenting with my new system.