Bcachefs
Bcachefs is a next-generation CoW filesystem that aims to provide features from Btrfs and ZFS with a cleaner codebase, more stability, greater speed and a GPL-compatible license. It is built upon Bcache and is mainly developed by Kent Overstreet.
Installation
To enable filesystem support and availability of user-space utils, add following line to the system configuration
/etc/nixos/configuration.nix
boot.supportedFilesystems = [ "bcachefs" ];
Usage
Format and mount a signle device
# bcachefs format /dev/sda
# mount -t bcachefs /dev/sda /mnt