Duperemove

Duperemove is a btrfs tool for finding duplicated extents and submitting them to the kernel for deduplication.

Usage
Detailed information can be seen by running.

Invocation
The following command shows how to deduplicate the filesystem; the hash file will be stored under the  directory:

Reading a file list created with fdupes
By passing the  option,  can work in conjunction with  in order to deduplicate a pre-calculated list of files. When in this mode, input will be accepted on stdin:

This is handy when a list of duplicates has already been created so that disk-intensive deduplication job can be ran at a time when the system is not under heavy load.

It is also possible to deduplicate directly from fdupes (without creating a file list):