Conflict resolution data set

The use of the IDCAMS command data set is no longer valid. A conflict resolution data set is generated by ARECOVER to simplify the resolution of like-named conflicts discovered during ARECOVER verification.

Each time ARECOVER verification processing cannot resolve a like-named conflict for a data set, the data set name is written to the conflict resolution data set with a default action of BYPASS. A message is issued indicating the name of the conflict resolution data set that was created. The name is generated as follows: id.agname.CONFLICT.Dyyddd.Thhmmss

The variables in the conflict resolution data set name are explained:

id: DFSMShsm authorized user ID.
agname: Name of the aggregate group being recovered.
yyddd: Julian date the ABACKUP was performed.
hhmmss: Time the ABACKUP was performed.

The aggregate group name, ABACKUP date, and ABACKUP time are used to make this conflict resolution data set unique to the recovery of a specific ABACKUP version.

An example of a conflict resolution data set is shown in Figure 1. It is a physical sequential data set with fixed-length 80 byte records.

Figure 1. Conflict Resolution Data Set

        /* CONFLICT RESOLUTION DATA SET                                      */
        /* AGGREGATE GROUP=agname, VERSION=nnnn                              */
        /* SPECIFY datasetname   action   ON EACH LINE                       */
        /* VALID ACTIONS ARE BYPASS, REPLACE,                                */
        /* RENAMESOURCE(level) or RENAMETARGET(level)                        */
        DATASETNAME1                                 BYPASS
        DATASETNAME2                                 BYPASS
        ⋮

To indicate different conflict resolution actions taken by ARECOVER verification processing for each data set entry in the conflict resolution data set, you may edit the conflict resolution data set before issuing the next ARECOVER command. As shown in Figure 1, the format of one line of the conflict resolution data set is a data set name followed by the action to be taken. The syntax of the action is the same as that of the ARECOVER command DATASETCONFLICT subparameters. Valid actions are RENAMESOURCE(level), RENAMETARGET(level), REPLACE, and BYPASS. Not all actions are valid for all data sets, based on restrictions discussed in topic Order of processing for conflict resolution.

When a subsequent ARECOVER command is issued and the conflict resolution data set exists, it is read and used as input to the verification process. If the conflict resolution data set does not meet format restrictions, a message is issued and ARECOVER processing continues, but ends following verification processing, even if EXECUTE has been specified. The conflict resolution data set is ignored during the verification process when this error occurs.

The lines containing conflict resolution actions are parsed for valid syntax, and data set names or qualifiers are also parsed for validity. If invalid syntax is found, or a data set name entry in the conflict resolution data set does not match the name of a data set entry in the ARECOVER control file, or a data set name entry is a duplicate of another entry, a message is issued and ARECOVER processing continues, ignoring the erroneous entries during verification processing.

When a like-named conflict is found for a data set name that has an entry in the conflict resolution data set, the action specified in the conflict resolution data set is used to attempt to resolve the conflict.

When VERIFY is specified, the action is not actually performed, but restrictions are validated. If the action in the conflict resolution data set is invalid for the data set, a message is issued indicating this, and if the conflict is not resolved by other conflict resolution processing, the data set fails verification. The verification process continues with the next data set.

When you use the ARECOVER command with the VERIFY parameter, a conflict resolution data set may be created. This conflict resolution data set contains entries for data sets that had a name conflict during verification processing, and a default action of BYPASS is indicated for these data sets. If you determine that the conflicts can be handled by either the RECOVERNEWNAMEALL, RECOVERNEWNAMELEVEL, or DATASETCONFLICT parameters on a subsequent ARECOVER command, then you delete the conflict resolution data set before issuing the command. If this deletion is not done, ARECOVER processing uses the conflict resolution data set action of BYPASS, and the data sets are skipped.

When EXECUTE is specified, the conflict resolution action is validated. If valid, the action is performed during data movement. If the action in the conflict resolution data set is invalid for the data set, a message is issued indicating this. If the conflict is not resolved by other conflict resolution processing, the data set fails verification, and is not recovered. ARECOVER EXECUTE processing continues for the remaining data sets. If an error occurs while performing the action during EXECUTE processing, a message is issued, and the data set is bypassed and not recovered.

When EXECUTE is specified, if all conflicts are resolved, and if all data sets in the aggregate group have been recovered—not bypassed through use of the conflict resolution data set—the conflict resolution data set and the RESTART data set are deleted. Data sets which are bypassed by a conflict resolution data set action of BYPASS cause the RESTART data set and conflict resolution data set to be retained and a unique return code to be set. The bypass of these data sets may be intentional, but since the default action placed in the conflict resolution data set is BYPASS, and the default is also to use the conflict resolution data set if it exists, the data sets may be bypassed unintentionally. In this case, deletion of the conflict resolution data set and RESTART data set would make the recovery of the remaining data sets difficult. If your analysis at this point shows that all desired data sets have been recovered, you may then manually delete the RESTART data set and conflict resolution data set.

If the conflict cannot be resolved, an entry is added to the conflict resolution data set indicating a default action of BYPASS (if there is not an entry already, no duplicate entries are created and the action for a current entry is NEVER modified). The data set is not recovered and processing continues. An entry is only added to the conflict resolution data set if the conflict cannot be resolved by any of the preceding actions.

If the conflict has been found for a component of a VSAM data set being verified, the source VSAM cluster name is added to the conflict resolution data set (not the individual component names).

If the data set has been renamed before verification by a RECOVERNEWNAMEALL or RECOVERNEWNAMELEVEL subparameter, the original data set name is used for the entry in the conflict resolution data set.

Each data set successfully verified is recovered if the EXECUTE parameter is specified.

The following conflict resolution actions are supported.

RENAMESOURCE(level)
Verification checks to see if a data set is already cataloged with the new name at the recovery site. If the source data set is a GDS, neither a GDS generation nor a related GDG base may exist for the new name (a unique message is issued indicating GDS/GDG base conflicts). Before recovery of a renamed GDS generation, a GDG base is defined with the proper new name by using the attributes of the source GDG base. If no like-named conflict is found for the new data set name, the data set is renamed when it is recovered with the new high-level qualifier.

If the new name would cause a like-named conflict, an appropriate message is issued and the data set is not recovered. If the original data set name is not already in the conflict resolution data set, an entry is created indicating the default action of BYPASS.

The RENAMESOURCE subparameter is not supported for ACCOMPANY data sets, or for migrated VSAM source data sets. In each case, a message is issued and the data set is not recovered. If the original data set name is not already in the conflict resolution data set, an entry is created indicating the default action of BYPASS.
RENAMETARGET(level)
Verification checks the attributes of the existing data set cataloged at the recovery site. If the target data set is one of the following, a message is issued, the target data set is not renamed, and an entry in the conflict resolution data set for the original data set name is created, indicating the default action of BYPASS.
- tape data set
- catalog
- GDS
- GDG base
In addition, the target data set MUST be one of the following to be eligible for rename:
- non-VSAM DASD
- VSAM base cluster
- VSAM alternate index (AIX)
- Data component, index component, or path related to a VSAM cluster or AIX (but not related to a catalog)
If the target object in conflict is a component or path related to a VSAM cluster or AIX, the entire target cluster, including component associations, is renamed.

Verification checks to see if a data set is already cataloged at the recovery site with the new name. If so, an appropriate message is issued, the target data set is not renamed, and the data set is not recovered. If the original data set name is not already in the conflict resolution data set, an entry is created indicating the default action of BYPASS.

If the data set meets restrictions for renaming and EXECUTE is specified, the existing data set at the recovery site is renamed. A message is issued indicating the action taken. When the conflict occurs for a component of a target VSAM data set, the entire target cluster, including associated components, is renamed. The indicated new high-level qualifier is used to rename the target objects. The ABACKUP data set is recovered with the original name. When the target data set is migrated, the RENAMETARGET action causes it to be recalled. If the rename action fails, a message is issued, and the data set is not recovered. If the original data set name is not already in the conflict resolution data set, an entry is created indicating the default action of BYPASS.

RENAMETARGET(level) performs an ALTER NEWNAME for the existing data set name. Special care should be taken when you change the high-level qualifier so that the existing data set does not become uncataloged, which may occur when no catalog alias exists for the new high-level qualifier.
BYPASS
The data set is not recovered during data movement. When a conflict occurs for a component of a source VSAM data set, the entire source VSAM cluster is bypassed and not recovered. A message is issued indicating the action taken.
REPLACE
Verification checks to see if the existing data set at the recovery site meets restrictions for data sets that may be deleted. If restrictions are not met, a message is issued, and the data set is not recovered. If the data set name is not already in the conflict resolution data set, an entry is created indicating the default action of BYPASS.
Note: When using the DSCONFLICT(REPLACE) parameter, the data set is deleted before attempting the recovery of the data set from the aggregate backup output files. If the recovery fails, the data set remains deleted. Causes of recovery failure include:
- I/O errors on the input tape
- Failure to allocate the new data set
- Recovering at a site that does not support the type of data set that is being recovered
If a GDG base exists and DSCONFLICT(REPLACE) has not been specified, recovery of the associated GDSs fails and an entry is placed in the conflict resolution data set with a default action of BYPASS.

If restrictions are met and EXECUTE is specified, the data set at the recovery site is deleted. When a conflict occurs for a component of a source VSAM data set, the entire target VSAM cluster related to the object in conflict is deleted. A message is issued indicating the action taken. If the delete for the REPLACE subparameter fails, a message is issued and the data set is not recovered. If the original data set name is not already in the conflict resolution data set, an entry is created indicating the default action of BYPASS.