How to back up my entire system with all components?

The most reliable way to backup your entire system would be to boot a live system and use a tool like clonezilla to create a (bootable) backup. Clonzilla, System Rescue

Here's one approach I use: Split the system into three parts: Base OS, Data, Key Applications

• Base OS is the stock Ubuntu system.
• Data is separate from the applications that process data.
• Key Applications (that process data sets) are containerized.

Backups: Only data is frequently backed up (it's valuable). The Key Applications container is snapshotted regularly for easy reversion if a problem occurs.

Upgrades: The OS and the Container are separate; an upgrade of one won't break the other. If an application upgrade breaks the stack in a container, I can revert to the last snapshot.

Migration: I can easily copy the container(s) and data to a different system without re-installing anything.

I can also clone the container for testing risky alternative applications or different versions. Or I can spin up a fresh container to rebuild everything from scratch. All without risking my working container, or my data, or the stability of my base OS.

There is some learning and maintenance involved: I use cron, LXD, and duplicity for snapshots, containers, and backups. I keep notes on how to install/uninstall everything in my containers, and links to those projects' instructions. I track the release schedules of the Base OS and Key Applications so I'm not surprised by a change. I set aside time to test changes and updates.

I would recommend RescueZilla https://rescuezilla.com/

It is use Clonezilla under the hood, but so much easier to use. Do a Backup and a Restore in just a few click. But like clonezilla, the system must be booted from the USB or DVD.

Personally I use ReaR, that I can schedule via a cron job,while system is running. I have done a couple of restore so far and it work well. https://relax-and-recover.org/

I will add to @BulletBob's recommendation for Clonezilla. This is the simplest and probably fastest way to recover from a crashed system. Here is an overview of the process:

1. Download Clonezilla and create a bootable USB. The steps are provided on the web site.
2. Get an external hard drive. It need not be an SSD, but should have enough space for the image of your computer's disk. Personally, I backup every month and keep 3 versions of backups. The backups might be much smaller than your primary disk, so you won't need exactly 3x of your primary disk.
3. Shut down your computer. Keep the external drive ready but DO NOT ATTACH IT NOW. Plug in the CLonezilla USB that you created above.
4. Start the computer and boot off the USB. You might need to hit some key like F12 to get to the boot menu and ask the computer to boot off the USB.
5. Accept the defaults. Choose the Disk to image option (not partitions). You can skip the disk checks -- your call.
6. Choose the source disk (this is your primary disk) that you want to make an image of.
7. At some point (depending on your version of Clonezilla), it will ask you to insert the destination disk. This is when you attach the external drive.
8. Select the external drive destination location.
9. Pick a location and backup image name or accept the defaults.
10. Kick off the backup. It might take a while. If you have a 250G drive, it can take up to 1 hour, depending on the speed of the USB which your external drive is connected to.
11. When done, follow the instructions to poweroff.
12. Remove the Clonezilla bootable USB and boot the system as usual. The external drive is still attached.
13. Once the system is up and running, verify that the backup files are present in the external drive.
14. Detach the drive and store it.

To recover, the process is simple.

1. Install a new disk (assuming the old one crashed).
2. Attach the external disk.
3. Boot off the Clonezilla USB.
4. Choose the restore option and go through the steps which are self-explanatory. Make sure to get the source and destination disks right.

HTH.