To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Reduce DASD free space fragmentation - DFDSS can be used to reduce DASD free space fragmentation. DFDSS (Data Facility Data Set Services) is a utility program in z/OS that provides various functions related to managing datasets and storage. It includes functions for managing free space on DASD (Direct Access Storage Device) by defragmenting free space.
Option B) Copy or move data sets from one DASD device to another or dump - DFDSS can be used to copy or move data sets from one DASD device to another or to create backups of datasets through a dump operation. These operations are commonly performed using the DFDSS utility.
Option C) Restore backup copies of entire DASD volumes - DFDSS can be used to restore backup copies of entire DASD volumes. It provides functions for backup and restore operations, allowing users to restore datasets or entire volumes from backup copies.
Option D) Increase File storage - DFDSS cannot be used to increase file storage. DFDSS primarily deals with managing datasets and storage, but it does not have the capability to increase the storage capacity of a file.
Based on the explanations above, the correct answer is D) Increase File storage. This option is incorrect because DFDSS cannot be used to increase file storage.