some things could be implemented as a journal ('timestamp on this file changed from X at time T' is much shorter than duplicating the entire block)
the filesystem can also be smarter about the location of blocks when it's accessing a block device more directly. One problem with doing snapshots at the block level is that you very quickly end up with a lot of seeking. The filesystem can be smarter about this.
in practice it may or may not matter, but there are enough places where it could matter that it's worth exploring.
Copyright © 2017, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds