TDMF moves of volumes that CA 11 files reside on

Products

• CA-11

Issue/Introduction

In the process of migrating the mainframe systems to a new Hitachi DASD array and noticed some of the volumes have CA 11 files on them.  The TDMF manual indicates the following:

If a volume that contains the job run history file (JEHF) is to be migrated, then the JEHF I/O must be shut
down before the migration. When the migration is completed, the task can be restarted

Please  confirm if the above is correct?  Can this be done without much impact to the system?

Resolution

The CA 11 data is in Datacom.  Datacom does  NOT recommend the use of TDMF to move Datacom files that are open for processing.

Datacom internally operates on data within its buffers, and optimizes its I/O according to the MUF's internal pipeline processing. In addition, Datacom can move records from one block to another, either in memory or on DASD, in order to make the best I/O use of the data blocks.  When you combine this data handling and moving internally to the MUF with the TDMF operation that is running with the database files open for processing, there is no way to guarantee that you have not added duplicates or lost "moved" records that change block locations.

 Datacom has a function called Online Area Move that  will be helpful with the move process.  The process  is used to make a "hot" move of a Datacom area (contained within a single file) into a new physical file on another volume. The key benefit here is that these Datacom files can be moved to the new Hitachi volumes without any outage for the CA 11 application.  During this process, you can resize the target file larger or smaller as needed, and the process works very quickly to move blocks in large groups at a time from the current physical file to a new physical file. Since all this happens within the Datacom environment, there is no concern for whether the data blocks are on DASD or in memory.  Datacom keeps track of each block's location to make sure no records are lost or duplicated.

All of the CA 11 files can be moved concurrently, and this is a relatively fast process. In addition, other key Datacom files (like the CXX and LXX), can also be moved using this function, with no application outage. Of course, if the MUF and CA 11 are shut down, you can use TDMF to move the files, provided you use the necessary parameters to maintain full track sizing.

 

Additional Information

To learn more about using this recommended approach and its requirements and restrictions, see the Datacom documentation for the DBUTLTY process  Online Area Move, and the sections that follows.