Allocating output copy data sets dynamically

Instead of using DD statements (each of which provides only a physical description of a single data set) you can use directives (output descriptors) to provide a logical view of how copy data sets are to be created. Allocating copy data sets dynamically with BMC AMI Copy allows you to accomplish the following tasks:

• Eliminate large, complex DD statements
• Greatly simplify tape stacking
• Restart a failed job automatically (no JCL or other statements to change)
• Automatically calculate disk space requirements
• Release unused space when a copy data set is closed
• Use wildcards in space names
• Use symbolic variables and generation data groups (GDGs) to assist in data set name generation
• Allocate full and incremental copies differently
• Allocate copies to different devices based on table space size
• Change to a different output descriptor based on the type of copy (full or incremental)

Because an output descriptor is not directly associated with a particular data set, you can use an output descriptor to describe multiple copy data sets.

The default BMC AMI Copy installation options module, ACP$OPTS, includes default descriptor options. During BMC AMI Copy installation, you can install additional, customized installation options modules, each with its own set of default descriptor options. Select the options module most suitable for your application and departmental needs by coding the options module parameter in the EXEC statement in your BMC AMI Copy job. Utility-parameters-on-the-EXEC-statement provides details.

To use the current default descriptor, use the name DEFAULT in the COPYDDN or RECOVERYDDN options in a COPY or COPY IMAGECOPY statement. To modify the current default descriptor, provide a new descriptor name in an OUTPUT statement and code the options you want to change. Any options not coded default to the corresponding values in the current default descriptor. Also, by using the DSNAME, COPYDSN, or RECOVERYDSN option in a COPY or COPY IMAGECOPY statement, you can override the default data set names without using an OUTPUT statement.

If you want full copies to be allocated to a different output descriptor or data set name than incremental copies, use the FULLDDN, FULLRECDDN, FULLDSN, and FULLRECDSN options with FULL AUTO or CHANGELIMIT on the COPY command. These options correspond to COPYDDN, RECOVERYDDN, COPYDSN, and RECOVERYDSN, respectively. If full copies are produced and FULLDDN, FULLRECDDN, FULLDSN, and FULLRECDSN are specified, they will be used. If they are not specified, COPYDDN, RECOVERYDDN, COPYDSN, and RECOVERYDSN are used.

BMC AMI Copy includes syntax to specify that full image copy data sets with an estimated size exceeding a specified size threshold should be allocated with different output descriptors or different data set names. The BIGDDN, BIGRECDDN, BIGDSN, and BIGRECDSN options work with the OUTSIZE installation option (see OUTSIZE=0) to provide this function as described below.

• If the value of OUTSIZE is met or exceeded and BIGDDN, BIGRECDDN, BIGDSN, and BIGRECDSN are specified, they will be used.
• If the value of OUTSIZE is met or exceeded and BIGDDN, BIGRECDDN, BIGDSN, or BIGRECDSN is not specified and FULLDDN, FULLRECDDN, FULLDSN, or FULLRECDSN is specified, FULLDDN, FULLRECDDN, FULLDSN, and FULLRECDSN will be used.
• If the value of OUTSIZE is met or exceeded and neither FULLDDN, FULLRECDDN, FULLDSN, or FULLRECDSN nor BIGDDN, BIGRECDDN, BIGDSN, or BIGRECDSN is specified, COPYDDN, RECOVERYDDN, COPYDSN, and RECOVERYDSN are used.

The use of OUTSIZE and the BIGDDN, BIGRECDDN, BIGDSN, and BIGRECDSN options provides a way for BMC AMI Copy to automatically copy large output copies to tape rather than DASD.

The following sections discuss the copy data set parameters that are defined in an output descriptor and provide examples of their use. Examples-of-BMC-AMI-Copy-jobs also provides detailed examples of JCL and SYSPRINT output for the dynamic allocation of output copy data sets.

This section contains the following topics: