On Sun, May 16, 2021 at 07:56:17PM +0200, Pascal Hambourg wrote: [snip how to do what I thought I wanted - thanks!]
I've realised the easiest thing to do will be to simply duplicate my existing xubuntu 20.10 installation on another partition. As before partitions are:- /dev/nvme0n1p2 ext4 48174 15782 29877 35% / /dev/nvme0n1p3 ext4 896193 295877 554724 35% /home /dev/sdb1 ext4 10016 183 9306 2% /boot /dev/sdb2 ext4 109596 33138 70850 32% /scratch /dev/sda1 ext4 938772 222397 668666 25% /bak /dev/sdc1 ext4 937872 77 890087 1% /mnt If I simply copy / to /mnt and also copy /boot to / how do I get grub to add the new partition to the boot menu? (/dev/sdc is a SATA disk so is visible to the BIOS so /boot can be on there with the OS) Then if, when I ugrade my 'main' xubuntu 20.10 to 21.04, it falls in a heap I can simply boot the xubuntu 20.10 on /dev/sdc1 and everything will still work as before (if a little more slowly). -- Chris Green
