$dataset_add = {
              'mandatory' => [
                                {
                                 'param1' => '$data-set-name-or-id',

                                }

                             ],
              'optional' => [
                                {
                                  'switch' => '-D',
                                  'value' => ''
                                },
                                {
                                  'switch' => '-N',
                                  'value' => '$node-name'
                                },
                                {
                                  'switch' => '',
                                  'value' => [$volume-name-or-id,$volume-name-or-id,$ossv-dir-name-or-id,$storage-system-name-or-id,$host-name-or-id    ]
                                },
                              ]
                        }