DASD can experience failures such as defective disk surfaces, drives,
and actuators. When these failures occur, data becomes inaccessible
to the operating system and could be lost. To prevent the loss of
the data, an installation should consider using the following to monitor
possible error conditions and correct any before they cause outages.
- The Environmental Record Editing and Printing (EREP) System Exception
Report
- Device Support Facilities (ICKDSF)
When a DASD error does occur, such as a defective track, an installation
can use z/OS® DFSMSdss to retrieve
the data from the defective areas and copy it to a backup DASD.