I have installed a new linux that boots off a USB 3 drive of 512 GB SSD. I also added a 4000 GB spinning disk on the other USB3 port.
Now using Timeshift to do a full backup and scheduling snapshots.
I also have 4 virtual machines configured. I made one, put everything I would ever want in the way of a chromebook on it, and cloned it 3 times. These are for browsing the web. If any browser catches a virus I simply destroy the VM and clone a new one. Takes 5 minutes.
If you have ever had a computer destroyed by a virus you will appreciate this latter technique.
My first backup only too the amount if time it took to write this post.