Comment by tobias3

The problem is that ZFS doesn't have an offline repair tool. A (granted unlikely) bit flip in an important data structure that gets written to disk makes the whole fs unmountable and that's it (idk if it has a tool to rescue file data from a unmountable pool? Maybe we should ask Gandi...).

With e.g. ext4 you can get back to a mountable state pretty much guaranteed with e2fsck. You might loose a few files, or find them in lost+found, etc. but at least you have something.

The reason ZFS doesn't have a offline repair tool is pretty convincing. Once you have zettabytes (that's the marketing) of data, running that repair tool will take too long, so you'd have to do everything to prevent that in the first place anyway. Including checksumming everything, storing everything redundantly and using ECC RAM.