Quiescing a data set

DFSMS and application programs can initiate a quiesce of DFSMStvs activity against a sphere across the sysplex. You can quiesce a sphere using the CICS® SET DSNAME command, the equivalent CEMT command, or the MVS™ VARY SMS command.

Recommendation: Be careful about quiesce with a path name; always use a base name.

Unlike CICS, DFSMStvs does not control the open requests and close requests of data sets that it accesses. DFSMStvs supports the ability to quiesce and close ACBs in a limited manner. If a data set is not currently open for DFSMStvs access, the data set is quiesced; otherwise, the quiesce of the data set is rejected. To quiesce a data set completely, ensure that it is not currently open in DFSMStvs mode; take these steps

Take these steps to quiesce a data set:

Display the jobs that use the data with the DISPLAY SMS,DSNAME operator command or the access method services SHCDS LISTDS(dsname) JOBS command.
Various levels of authorization are required to use the SHCDS parameters. For information about this authorization, see z/OS DFSMS Access Method Services Commands.
Either allow those jobs to complete normally or cancel them. An in-flight unit of recovery is backed out if it is cancelled.
Use the VARY SMS,SMSVSAM,SPHERE command, or an equivalent CICS command, to quiesce the data set.
Recommendation: Be careful about quiesce with a path name; always use a base name.
Perform the operation or operations that required the data set to be quiesced.
Use the VARY SMS,SMSVSAM,SPHERE command, or an equivalent CICS command, to enable the data set for DFSMStvs and CICS.
When you specify data sets for a VARY SMS,SMSVSAM,SPHERE command, the data sets are not necessarily quiesced in the order in which you specified them or in any other order. When you use an asterisk (*) to specify data sets, they are not necessarily quiesced alphabetically or in any other order. So, when the last data set that you specified is quiesced, the other data sets that you specified might not have been quiesced yet. Do not issue a quiesce command for a particular data set until the previous operation on that data set completes.

For example, if an operator at a console enters VARY A QUIESCE followed by VARY A ENABLE, either command could take effect first. Also, the operator could enter the VARY QUIESCE or VARY ENABLE command with a path name while someone else enters one of these commands with a base name, and either command could take effect first.

Recommendation: Be careful about quiesce with a path name; always use a base name.

DFSMStvs supports the following VSAM IDAQUIES macro quiesce types:

QUICLOSE: Quiesce and close ACBs
QUIOPEN: Unquiesce
QUICOPY: Quiesce for COPY operation
QUICEND: End of quiesce for COPY operation
QUIBWO: Prepare for BWO copy operation
QUIBEND: End of prepare for BWO copy operation
QUIFRC: Forward recovery complete
QUICMP: Completion of quiesce processing
QUICA: Cache available