IBM SC34-7012-01 manual File closing non-RLS mode, Restriction for Vsam upgrade set

vIf the file was defined with BACKUPTYPE(STATIC) and the ICF catalog indicates that the data set is already ineligible for BWO, the ICF catalog is not updated.

However, if the ICF catalog indicates that the data set is currently eligible for BWO, IGWABWO makes it ineligible for BWO and sets the recovery point to the current time. CICS issues an attention message; you should discard any BWO backup copies already taken in a previous batch window.

File closing (non-RLS mode)

When the last file that is open for update is closed against a VSAM base cluster data set, CICS uses the DFSMSdfp IGWABWO callable service to update the ICF catalog to indicate that the data set is no longer eligible for BWO and to reset the recovery point to the current time.

If a VSAM split has occurred while a file was open, CICS calls IGWABWO at file-close time to update the ICF catalog to prevent further BWO backups. If DFSMShsm is currently taking a BWO backup, it will discard the backup at the end of the backup operation.

The BWO attributes indicating that a split has occurred and that the data set is eligible for BWO are restored when the next file is opened for update against the data set. This ensures that DFSMShsm takes the correct action if a split occurs during backup processing, which spans CICS updating a file (causing a VSAM split), the file being closed, and then the file being reopened.

When CICS is terminated by a normal shutdown, all CICS files are closed. The ICF catalog is updated to suppress BWO activity during the batch window between CICS sessions. After an uncontrolled or immediate shutdown, or if there is a failure during file closing, the data set remains open and the BWO flags are not reset. See “Shutdown and restart” on page 213.

Restriction for VSAM upgrade set

In some circumstances, it might not be possible to take either BWO or non-BWO backups of a data set. The VSAM UPDATE ACB ENQs for a sphere might remain, even though there are no files open for update against this sphere. This could happen if a VSAM sphere contains an AIX in the upgrade set and the following actions occur:

1.The sphere is opened for update via a VSAM path. This causes VSAM to open for update all upgrade clusters for this sphere.

2.A file is opened for read-only against this sphere.

3.The original VSAM path is closed.

The data set is now ineligible for BWO backups because CICS file control has reset the BWO attributes in the ICF catalog. But, until all open ACBs in the sphere are closed, VSAM will not close the internal ACBs that are open for update, and thus it is not possible to take non-BWO backups either.

To remedy this situation, either:

vClose all ACBs for the sphere, or

vOpen for update against the base cluster data set a file that is defined with

BACKUPTYPE(DYNAMIC).

212CICS TS for z/OS 4.1: Recovery and Restart Guide