Operation Concerns

Merge is designed to run on a scheduled basis, based on your installation's needs. As stated previously, disk-to-disk merge can be run on a daily basis, since it requires no operator intervention and can quickly free up DASD space. For tapes, merge is usually run on a weekly or monthly basis, depending on the number of archive volumes created and the amount of space that can be recovered from them. Not all CA Disk archive volumes need to be run through merge. Process only those volumes that are wasting a large amount of space, or those archive data sets on disk that can now be moved to tape for the remainder of their retention period.

During a merge run, input 3480 cartridges use the DD statement //ARCHIVER, while input disk drives are referenced using the DD statement //ARCHIVED.

Therefore, depending on what is being merged, one tape and/or one 3480 drive will be needed for input. Since the ARCHVOLS records contain device type information and data set names, CA Disk can dynamically allocate each of these input types as appropriate. (JCL can be provided for tape and 3480s, if desired.)

If the output is to disk, CA Disk always allocates the disk archive data set dynamically. To allocate all primary output devices dynamically, the data set names and the device types must be supplied in sysparms MERPnNAM and MERPnTYP. Concurrent duplicate output copies can also be created and dynamically allocated by supplying proper values for sysparms MERCnNAM and MERCnTYP. If the concurrent copies are not wanted, sysparms MERCnTYP must be set to NULL. Concurrent tertiary output copies can also be created and dynamically allocated by supplying proper values for sysparms MERTnNAM and MERTnTYP. By default, the MERTnTYP is set to NULL, so no concurrent tertiary copies are produced. For more information about these sysparms, see their sysparm descriptions in the Systems Guide.

(Tape or 3480 devices can be allocated via JCL if desired by supplying //ARCHIVE1, //ARCHIVE2, .... DD statements for the primary output, //ARCHIVC1, //ARCHIVC2, .... for the copy devices, and //ARCHVT1,//ARCHVT2, .... for the tertiary devices.)

You can optionally specify a system parameter that allows the computer operator to terminate merge prematurely (a graceful shutdown). Message 4254 is issued to the operator at the beginning of the merge process. If the operator replies to the message to indicate that Merge processing is to be stopped, a response of END will terminate the job at the end of the current input volume or a response of NOW will terminate the job at the end of the current data set. Processing will complete normally, and all reports and statistics will be generated as normal. This option permits you to start merge and run until the resources are needed for something else. Thus merge can be run in otherwise unused machine time. Specify this option through sysparm MERREPLY.