When the British Library was hit by ransomware, some systems were down for months. They were old software that didn't run on the newer more secure systems the library had to migrate to. And there was no funding to rewrite them, not without cutting already affected services.

So you pull everything off the shelves, enter it into the system, then reshelve it.

The library has something like 5 million books. How many could you enter into an empty system each day? Maybe 1000? That would take a decade to complete.

should be simple, restore from backup. right ?