sharedextents - show proportion of physical extents shared between two files

Discover when two files on a CoW filesystem share identical physical data.

Warning: Proof-of-concept. Alpha quality software, use at your own risk.

See Also:

• fienode, for finding identical matches via a hash.
• filefrag -v, for listing physical extents.

Installation

From source

go get github.com/pwaller/sharedextents

Binary Download

See releases.

• sharedextents-linux-amd64 v1.0

Usage: sharedextents <a> <b>

For example:

$ sharedextents a b
1142734848 / 1679605760 bytes (68.04%)

# (note: files a and b share some physical extents)

Exit is status 0 if extents are shared between a and b, and 1 otherwise.

Caveats

There may be bugs. This will delete all your data and eat your cat. When it does, that is your problem. Keep backups, folks.

License

MIT.