anchor.diff:            to exclusively use ZFS commands to manage filesystems. If so, since NixOS/systemd
             will not be managing those filesystems, you will need to specify the ZFS pool here
             so that NixOS automatically imports it on every boot.
  +        '';
  +      };
  +
  +      devNodes = mkOption {
  +        type = types.path;
  +        default = "/dev";
  +        example = "/dev/disk/by-id";
  +        description = ''
  +          Name of directory from which to import ZFS devices.
  +
  +          Usually /dev works. However, ZFS import may fail if a device node is renamed.
  +          It should therefore use stable device names, such as from /dev/disk/by-id.
  +
  +          The default remains /dev for 15.09, due to backwards compatibility concerns.
  +          It will change to /dev/disk/by-id in the next NixOS release.
           '';
         };
   
  
positive.code:             done
              ''] ++ (map (pool: ''
              echo "importing root ZFS pool \"${pool}\"..."
              zpool import -d /dev/disk/by-id -N $ZFS_FORCE "${pool}"
          '') rootPools));
        };
  
  
negative.code:             };
              script = ''
                zpool_cmd="${zfsUserPkg}/sbin/zpool"
                ("$zpool_cmd" list "${pool}" >/dev/null) || "$zpool_cmd" import -d ${cfgZfs.devNodes} -N ${optionalString cfgZfs.forceImportAll "-f"} "${pool}"
              '';
            };
        in listToAttrs (map createImportService dataPools) // {
  