Installing the Basic System › Defining the CA EPIC for z/VSE Resource Dataset (ERD)

Defining the CA EPIC for z/VSE Resource Dataset (ERD)

An ERD file is only required for:

1. sharing tape devices among multiple VSE machines or LPARS.
2. defining required ACL related information.
3. defining the real (3 or 4 digit) device address associated with a virtual device if the AUTOATTACH feature is used.

To share tape devices, a Unit Control Block (UCB) must be created for each tape device (reel or cartridge type) that is accessible by CA EPIC for z/VSE. UCBs contain device number and attribute information that CA EPIC for z/VSE needs for device allocation and deallocation. They are located in the CA EPIC for z/VSE Resource Dataset (ERD).

An ERD is not required for a single-image system that does not use an ACL.

The ERD provides a single repository of tape characteristics and ownership information. Only one ERD is used in a tape-sharing environment. For example, if CPU A, CPU B, and CPU C are sharing a group of tape devices, only one ERD needs to be created. CA EPIC for z/VSE programs running on these CPUs will all use this ERD.