How to create a bootable backup in a single drive multiboot system

Hi All,
Currently I have installed macOS Mojave (UEFI mode - clover bootloader) in a 250 gb APFS partition on a 500 gb SSD drive. Now I would like to create a mutiboot system by installing macOS Catalina on a second 250 gb APFS partition (which I had previously created) on the same drive.
Before this, however, I would like to prepare a bootable backup of this system using a 1 tb HDD, reserving 500 gb for system backup and managing to use the remaining 500 gb for data storage.
Is it possible to make this backup configuration? How can I do and which software to use?
Thanks in advance for Your help

First of all, if you are going to use APFS for both Mojave and Catalina, do not use separate partitions.
Install Mojave, then use disk utility to create a second VOLUME (not a partition). Install Catalina to this volume.
You can then use either SuperDuper or CarbonCopyCloner to clone to the other drive. To make it bootable, copy your SSD EFI partition to the HDD EFI partition.

Going Bald said:

First of all, if you are going to use APFS for both Mojave and Catalina, do not use separate partitions.
Install Mojave, then use disk utility to create a second VOLUME (not a partition). Install Catalina to this volume.
You can then use either SuperDuper or CarbonCopyCloner to clone to the other drive. To make it bootable, copy your SSD EFI partition to the HDD EFI partition.

Click to expand...

The current configuration of my system is described here:
Unfortunately I had created both partitions when installing macOS Mojave in anticipation of installing the next version of macOS as I had done with Sierra / High Sierra.
Could I delete the second partition by expanding the first and then create the new volume on which to install macOS Catalina?
Can I also create a second partition (in addition to the one reserved for the backup system) in the unused space of the backup HDD for data storage?

SardusX said:

The current configuration of my system is described here:

Install macOS Catalina in a second partition (volume?) alongside macOS Mojave

Hi All, When I installed macOS Mojave I reserved a partition equivalent to half ssd to it and created a second hfs+ partition for the next version. This is the current situation on macOS Mojave SSD: /dev/disk2 (internal): #: TYPE NAME SIZE...

www.tonymacx86.com

Unfortunately I had created both partitions when installing macOS Mojave in anticipation of installing the next version of macOS as I had done with Sierra / High Sierra.
Could I delete the second partition by expanding the first and then create the new volume on which to install macOS Catalina?
Can I also create a second partition (in addition to the one reserved for the backup system) in the unused space of the backup HDD for data storage?

Click to expand...

Yes, you should be able to delete the partition, extend the first to take in the free space left behind and then create the new volume.
Or you could leave it and install Catalina on it. Although you can, it is better to use volumes within the Mac OS when using APFS formatting, but you might want to stick with the familiar until you learn the rules for working with APFS formatted volumes..

For the storage drives you can create as many partitions as you wish.

Going Bald said:

Yes, you should be able to delete the partition, extend the first to take in the free space left behind and then create the new volume.
Or you could leave it and install Catalina on it. Although you can, it is better to use volumes within the Mac OS when using APFS formatting, but you might want to stick with the familiar until you learn the rules for working with APFS formatted volumes..

For the storage drives you can create as many partitions as you wish.

Click to expand...

Thanks for Your reply,
I would like to use a 1 tb HDD to create a backup drive for the macOS Mojave / macOS Catalina multiboot system drive + a partition for data storage.
I thought of doing this using Disk Utility:
- Erase the backup drive using the APFS format - GUID partition table
- Add two APFS volumes (2x250 gb) to backup respectively macOS Mojave / macOS Catalina
- Partition the backup drive by adding an EX FAT partition (1x500 gb) for data storage
- Mount system and backup drives EFI partitions
- Create in Carbon Copy Cleaner tasks for backup EFI System Folder and macOS Mojave/macOS Catalina system volumes
Please, could you report any errors or add hints (in your opinion) about this to-do list to create the backup drive?