Converting to SMS management without data movement

To convert data to SMS management, use the CONVERTV command with the SMS keyword. (Because SMS is the default for the CONVERTV command, you can simply specify CONVERTV.) Of course, the volume and all its data sets must be eligible for conversion to successfully run CONVERTV with SMS.

If the volume is eligible for conversion, the INITIAL indicator on the volume is set. This means the volume is in the same state as when you specify the CONVERTV command with the PREPARE keyword. When a volume has its INITIAL indicator set on, DFSMSdss begins processing the data sets on the volume.

If a data set is eligible for conversion, ACS is called to assign SMS classes to the data set. When you use the CONVERTV command with SMS, you are in the ACS CONVERT environment. The storage class ACS routine is executed first. If the storage class assigned is not null, the management class ACS routine is executed. For a list of variables available to ACS routines during CONVERTV processing, see ACS variables available during RESTORE and CONVERTV processing.

RACF® checks if the RESOWNER of a given data set is authorized to define the data set with the given STORCLAS, MGMTCLAS, or both. Ensure that the RESOWNER has the correct authority.

If no errors occur, the catalog entry for the data set is updated to include the classes. For VSAM data sets, the catalog entry is updated to indicate that it is SMS-managed. For non-VSAM data sets, a catalog entry is added that indicates the data set is SMS-managed. After the catalog updates and additions are successfully made, the data set’s VTOC entry is updated to indicate it is SMS-managed.

If a VSAM data set has the guaranteed-space attribute, a check is done to verify the eligibility of its candidate volumes. If this check fails, the data set is not converted to SMS management. Non-VSAM data sets have candidate volumes in their catalog entries made nonspecific.

When DFSMSdss encounters a data set that is not eligible for conversion, it does not process the data set, but it continues to process other data sets on the volume. The only time conversion of data sets stops is when an error prevents ACS from returning class information for any data set.

DFSMSdss does not mark a volume as SMS-managed until all the data sets on the volume are SMS-managed. If a volume contains data sets that are ineligible for conversion, you must take some action to make them eligible or move them off the volume. You can then resubmit the CONVERTV command to convert any data sets not already converted and mark the volume as an SMS-managed volume.

On subsequent invocations of CONVERTV processing, DFSMSdss processes only those data sets not yet converted unless you specify the REDETERMINE keyword. If REDETERMINE is specified, DFSMSdss processes data sets already converted if their SMS management class or SMS storage class do not match those returned by the current ACS routines and data sets not yet converted. You may want to do this if your ACS routines changed since the last time you ran the CONVERTV operation on the volume.