Copied system partitions to USB disk, how to proceed to make a clone?

[Bo Berglund]

On Tue, 19 Oct 2021 17:59:26 +0200, Bo Berglund <bo.berglund at gmail.com> wrote:

>I guess that means I have to again try and boot off the installation USB and use
>GParted from there?

Seems like this system is not so easy to boot from a USB key anymore...
I inserted the Ubuntu 20 install USB and rebooted (from Ubuntu) and got back to
the boot menu of the main drive where there was no sign of any USB boot being
offered.

So in this case, how do I get to use GParted in the ubuntu usb or in the GParted
Live USB?

>QUESTION
>--------
>Can I have another Ubuntu (my old server) as a boot menu item on this PC?
>I.e. can I copy in the system partition and then modify the boot loader setting
>such that it can select between Ubuntu 20.04 and Ubuntu 18.04?
>How can that be done?

Once I get to use GParted I can set it up as follows (I believe)
- Shrink the current Ubuntu 20 partition from 415 GB to 40
- Copy the 30 GB ubuntu 18 partition from backup
- Create a 80 GB empty partition
- Copy the 264 GB home partition from backup
- Fix the boot loader so it includes the Ubuntu 18 system too (how?)

Now, if I can boot the Ubuntu18 partition it will attach the home partition
because fstab is set to use UUID mounts. So it "should" work, I believe.

But:
- How to boot to USB now so I can repartition?
- How to add a new OS to the boot loader (grub?)


-- 
Bo Berglund
Developer in Sweden