Medial initialization includes the actions of minimal initialization, and the validation of the existence and content of the track's home address and record 0 for every track in the specified range. Validation ensures that the proper track address (cylinder and head) appears in both the home address and record 0 on the track, and that a standard record 0 exists on the track. Validation rewrites the home address and record 0.
A volume is initialized at the medial level when both the VALIDATE and NOCHECK options are specified.
At the completion of the medial initialization processing for the requested tracks, defective primary tracks that were using an alternate are now assigned alternates in sequential order within the alternate track area.
If a medial initialization does not run to completion, the CONTINUE function is provided to allow you to recover in a minimum amount of time, and to ensure the volume is usable. For more information concerning continuing after a failure, see Resuming after a job or system failure.
When you are performing a medial initialization for a CKD device that is being emulated on an IBM 9313, 9332, or 9335, the CONTINUE function is not supported and range parameters are ignored.
Before running a medial initialization (or any ICKDSF job), the devices must establish thermal stability. For more information, see Devices supported by ICKDSF.
Medial initialization is not supported for dual copy volumes or real 3390-9 devices.