My backup contains files and old versions of files I no longer have on the primary storage. It is much more than a 1:1 copy, and can not be recreated. I need t

My backup contains files and old versions of files I no longer have on the primary storage. It is much more than a 1:1 copy, and can not be recreated. I need to feel safe that I can reasonably undo my changes on the primary storage, even if it takes me years to realise what I did. This is why I keep two backups. Until now, the secondary offsite copy was on ACD...