DFSMSdfp: Back up SMS control data sets
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.
Table 1 provides more details about this migration action. Use this information to plan your changes to the system.
| Element or feature: | DFSMSdfp. |
|---|---|
| When change was introduced: | General migration action not tied to a specific release. |
| Applies to migration from: | z/OS V2R1 and z/OS V1R13. |
| Timing: | Before installing z/OS V2R2. |
| 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 V2R2 systems:
- Back up SMS control data sets according to established procedures in the event that fallback is required. The control data set format is VSAM linear.
- Install all coexistence PTFs in Install coexistence and fallback PTFs.
In addition, if you modified and activated a higher-level policy on a pre-z/OS V2R2 system, do the following to ensure that the ACDS can be accessed on z/OS V2R2 and that the SMS control block reflect the new lengths and control information:
- On the pre-z/OS V2R2 system, save the active ACDS as an SCDS with the SETSMS SAVESCDS command.
- On z/OS V2R2, update, translate, validate, and activate the saved SMS policy.