(file-systems (append
                (list
                 (file-system
                  (device (file-system-label "root"))
                  (mount-point "/")
                  (type "btrfs")
                  (options "noatime,subvol=@"))
                 (file-system
                  (device (file-system-label "efi"))
                  (mount-point "/boot/efi")
                  (type "vfat"))
                 (file-system
                  (device (file-system-label "home"))
                  (mount-point "/home")
                  (type "btrfs"))

                 (file-system
                  (device (file-system-label "root"))
                  (mount-point "/gnu")
                  (type "btrfs")
                  (options "subvol=@/gnu,compress-force=zstd:3")))
                %base-file-systems))