EXPORTING › EXPORT Optional Parameters › MERGIN › How an Export with MERGIN Works on Multiple Catalogs

How an Export with MERGIN Works on Multiple Catalogs

The file read from MERGIN may contain the output from any number of catalogs. Whenever the catalog changes, the currently open catalog is marked as being at end-of-file and is closed. The new catalog is then opened and processing continues.

An incremental backup must begin with a catalog export. The EXPORT file contains all clusters currently in the catalog or catalogs.

Following are the incremental backups in the context of a catalog export that begins on Monday.

1. The catalog export file is used as MERGIN input to Tuesday's run. The FVROUT file contains one of the following options:

   MERGIN=ddname

   Copies all clusters not updated on Tuesday from MERGIN to FVROUT. All clusters defined or updated on Tuesday are copied from disk to FVROUT, and clusters deleted on Tuesday are not carried forward to FVROUT. Except for some messages, this is the same as a catalog export.

   MERGIN=ddname CARRY

   Writes all new, updated, and not updated clusters to FVROUT. In addition, any clusters deleted on Tuesday are copied from MERGIN to

   FVROUT. The FVROUT file contains the current status of all clusters that have existed since the Monday backup.

   MERGIN=ddname DROP

   Copies from disk to FVROUT only those clusters created or updated on Tuesday. This file contains the most active files in the system. Since fewer clusters are backed up, the export runs faster. To find which export file contains clusters that were dropped because they were not updated, you must save the export listings.

2. The FVROUT file from Tuesday is merged into Wednesday's run. Wednesday's FVROUT content is determined by the options described in stage 1.