The RECOVER utility and the DFSMSdss RESTORE command
The RECOVER utility can run the DFSMSdss RESTORE command, which generally uses extensions that are larger than the primary and secondary space allocation values of a data set.
The RECOVER utility runs this command if the point of recovery is defined by an image copy that was taken by using the CONCURRENT option of the COPY utility.
When the RECOVER utility chooses a system-level backup for object-level recovery, DFSMShsm is used to restore the data sets from the system-level backup.
The DFSMSdss RESTORE command extends a data set differently than Db2, so after this command runs, you must alter the page set to contain extents that are defined by Db2.