On Tue, 15 Apr 2025, at 11:09, Pádraig Brady wrote: > Right. Users would use --sparse in an attempt to be space efficient, > but in this case the reflink is more space efficient and so takes precedence.
I see the logic, but in this case I'm using cp not to duplicate, just to sparse-ify, then delete the original. It would be fair to say "don't use cp if you don't want a copy", but there aren't many tools which can do this. Probably `fallocate --dig-holes` is better, as seen from its manpage: You can think of this option as doing a "cp --sparse" and then renaming the destination file to the original, without the need for extra disk space. Cheers, Phil