On 07/02/2014 12:57 PM, m.roth at 5-cent.us wrote: > I think the buzzword you want is dedup. dedup works at the file level. Here we're talking about files that are highly similar but not identical. I don't want to rewrite an entire file that's 99% identical to the new file form, I just want to write a small set of changes. I'd use ZFS to keep track of which blocks change over time. I've been asking around, and it seems this capability doesn't exist *anywhere*. -Ben