bsdisbetter https://www.dragonflybsd.org/docs/how_to_implement_hammer_pseudo_file_system40pfs41_slave_mirroring_from_pfs_master/
joelkp For HAMMER2, the feature is still missing, unlike for the older HAMMER. The closest workaround is to use the 'cpdup' program, which duplicates what is in one location to another.