If this message has been issued as a result of a volume space management request, DFSMShsm has received a space management request that is either missing the required UNIT parameter or that has the UNIT parameter specified with an unsupported device type.

If this message has been issued as a result of a request to migrate an individual data set, the volume on which the data set resides is a type of volume that is not supported by DFSMShsm. This volume can be either a volume that is not managed by DFSMShsm or a primary volume that has not been added to this particular processing unit. For this type of migration, DFSMShsm has scanned the device table for the device type for the volume, but the type has not been found. See z/OS DFSMShsm Implementation and Customization Guide for a list of supported devices.