SMS managed APF datasets display their actual volser unless that cannot be verified, in which case the value *SMS* is used. Reasons that datasets cannot be verified include:
- The dataset is not currently on the explicit volume set for it.
- The dataset is on a volume that is not currently online.
- The LOCATE macro said the dataset was not currently cataloged.
- The OBTAIN macro gave an error.
- The volser is not currently supported.
Running the ev390dapf.pl script in debug/trace mode will output the reason that the dataset cannot be verified.