reference commands build a db (read only) duperemove -rA --hashfile=/opt/freestation/dedupremove.hash /home/ # btrfs fi df /home Data, single: total=617.00GiB, used=577.94GiB System, DUP: total=8.00MiB, used=112.00KiB Metadata, DUP: total=3.00GiB, used=1.27GiB GlobalReserve, single: total=512.00MiB, used=0.00B duperemove -drA --hashfile=/opt/freestation/dedupremove.hash /home/ # btrfs fi df /home Data, single: total=617.00GiB, used=537.03GiB System, DUP: total=8.00MiB, used=112.00KiB Metadata, DUP: total=3.00GiB, used=1.24GiB GlobalReserve, single: total=512.00MiB, used=0.00B