The two sides of reflink()

Netapp's .snapshot and the similar functionality reflinks can provide will give you semantics similar to a backup (a version of the file from a particular point in time, which will stay there until your backup regime removes it as too old). So it's a big improvement on DOS's "maybe you'll be able to grab the data back before the space is recycled by the filesystem". So it should at least have reliable, predictable semantics for things like accidental deletion.

Although in practice it's going to get used to undo rm occasionally, it seems to me only sensible to have something like this available so I'm able to roll back important documents and settings to previous states if I make the wrong modification, or if some program barfs over everything and corrupts things.

Users will probably have to be repeatedly reminded that, yes, they do need an independent backup on another disk somewhere because reflinks won't save you if your computer explodes. But most folks don't do proper backups *anyhow*, so I doubt it'll make that aspect of user behaviour much worse!