Description: In a multisystem Storage Management Subsystem (SMS) complex, operating systems share a common set of SMS classes, groups, ACS routines, and a configuration base, which make up the storage management policy for the complex. This storage management policy is maintained in a source control data set (SCDS). When this policy is activated for SMS, the bound policy is maintained in processor storage and on DASD in an active control data set (ACDS). Systems in the complex communicate SMS information through a common communications data set (COMMDS).
It is recommended that to successfully share SMS control data sets in a multisystem environment where there are mixed levels of DFSMS, you update, translate, validate, and activate SMS policies on the system with the latest level of DFSMS. When an earlier control data set is to be updated or activated, the control data set is formatted by the later-level system. The shared SMS control blocks reflect the new, rather than the previous, lengths and control information.
For fallback, IBM® recommends restoring SMS control data sets from backups taken on the fallback release.
Editing a policy on an earlier system could invalidate unused control information and prevent the control data set from being accessed by a later system. A warning message is provided before a policy can be changed on an earlier system. ACS routines may need to be updated and translated so to not reference policy items not known to the earlier system.
Remember, you risk policy activation failures if SCDS changes are not validated using the latest-level system in a sysplex.
| Element or feature: | DFSMSdfp. |
| When change was introduced: | General migration action not tied to a specific release. |
| Applies to migration from: | z/OS V1R13 and z/OS® V1R12. |
| Timing: | Before installing z/OS V2R1. |
| Is the migration action required? | No, but recommended to ensure data integrity. |
| Target system hardware requirements: | None. |
| Target system software requirements: | None. |
| Other system (coexistence or fallback) requirements: | Install the PTFs in Install coexistence and fallback PTFs if they are not already installed. |
| Restrictions: | None. |
| System impacts: | None. |
| Related IBM Health Checker for z/OS check: | None. |
Steps to take: Do the following on your pre-z/OS V2R1 systems:
In addition, if you modified and activated a higher-level policy on a pre-z/OS V2R1 system, do the following to ensure that the ACDS can be accessed on z/OS V2R1: