Using indirect catalog entries

Indirect cataloging, also known as indirect volume serial support, allows the system to dynamically resolve volume and device type information for non-VSAM, non-SMS-managed data sets that reside on the system residence (IPL) volume when accessed through the catalog. This allows you to change the volume serial number or device type of the system residence volume without also having to recatalog the non-VSAM data sets on that volume.

Extended indirect volume serial support allows catalog entries to be resolved using system symbols defined in an IEASYMxx member of parmlib, so that indirect references can be made to one or more logical extensions to the system residence volume. Like indirect catalog support, this support lets you change the volume serial numbers or device types of system software target volumes without having to recatalog their non-VSAM data sets. Therefore, you can have multiple levels of z/OS® data sets residing on multiple sets of volumes with different names and device types, and use them with the same master catalog.

Furthermore, extended indirect volume serial support includes a system-defined static symbol, &SYSR1. The value of &SYSR1 is automatically set to the volume serial of the IPL volume. If you name your system residence volumes and their extensions according to a pattern, you can use substrings of the &SYSR1 symbol to assign substitution text to symbols for the other volumes.

Using indirect catalog entries, together with the extended support, allows you to share master catalogs among multiple images that use different volumes with different names for the system residence volumes and their extensions. You can also do this using a single SYMDEF for all images in a shared parmlib data set. Thus, once set up, no future updates should be needed to continue using this support.

For details about IEASYMxx parmlib members and how to define system symbols to use with indirect volume serial support, see z/OS MVS Initialization and Tuning Reference . For details about how to use indirect volume serial support itself, see z/OS DFSMS Access Method Services Commands .