I’m trying to do that; but all of the newer drives i have are being used in machines, while the ones that arent connected to anything are old 80gb ide drives, so they aren’t really practical to backup 1tb of data on.
It’s possible to make that work; through discipline and mechanism.
You’d need like 12 of them but if you’d carve your data into <80GB chunks, you could store every chunk onto a separate scrap drive and thereby back up 1TB of data.
Individual files >80GB are a bit more tricky but can also be handled by splitting them into parts.
What such a system requires is rigorous documentation where stuff is; an index. I use git-annex for this purpose which comes with many mechanisms to aid this sort of setup but it’s quite a beast in terms of complexity. You could do every important thing it does manually without unreasonable effort through discipline.
For the most part i prevented myself from doing the same mistake again by adding a 1gb swap partition at the beginning of the disk, so it doesn’t immediatly kill the partition if i mess up again.
Another good practice is to attempt any changes on a test model. You’d create a sparse test image (truncate -s 1TB disk.img), mount via loopback and apply the same partition and filesystem layout that your actual disk has. Then you first attempt any changes you plan to do on that loopback device and then verify its filesystems still work.