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VSAM files accessed in RLS mode
If you specify file definitions that open a data set in RLS mode, specify the
recovery options in the ICF catalog.
The recovery options on the CICS file resource definitions (RECOVERY,
FWDRECOVLOG, and BACKUPTYPE) are ignored if the file definition specifies
RLS access.
The VSAM parameters LOG and LOGSTREAMID, on the access methods services
DEFINE CLUSTER and ALTER commands, determine recoverability for the entire
sphere. Locating these recovery parameters in the ICF catalog enforces the same
options, for all CICS regions in the sysplex, for all the files opened against a given
sphere.
LOG({NONE|UNDO|ALL})
Specifies the type of recovery required for the VSAM sphere. Specify the LOG
parameter for data sets that are to be used by CICS in RLS mode.
NONE
The sphere is not recoverable.
UNDO
The sphere is recoverable. CICS must maintain system log records for
backout purposes.
ALL
The sphere is recoverable for both backout and forward recovery. CICS
must maintain system log records (as for UNDO) and forward recovery log
records. If you specify LOG(ALL), also specify LOGSTREAMID to indicate
the name of the forward recovery log.
Note: Forward recovery support is available for recoverable files
only—you cannot have forward recovery without backout recovery.
LOGSTREAMID(log_stream_name)
Specifies the name of the log stream to be used for forward recovery log
records when LOG(ALL) is defined. Note that IDCAMS does not check for the
presence of the LOGSTREAMID during DEFINE processing. CICS checks for a
log stream name when attempting to open a data set defined with LOG(ALL),
and the open fails if the log stream is not defined and cannot be created
dynamically.
If you omit the LOG parameter when defining your VSAM data sets, recovery is
assumed to be UNDEFINED, and the data set cannot be opened in RLS mode. You
can also set the UNDEFINED status explicitly by specifying NULLIFY(LOG).
For information about the access methods services DEFINE and ALTER commands,
see z/OS DFSMS: Access Method Services for ICF and z/OS DFSMS: Using data sets.
Inquiring on recovery attributes:
You can use CEMT, or EXEC CICS, INQUIRE FILE and INQUIRE DSNAME
commands to determine the recovery options that are specified for files and data
sets.
The INQUIRE FILE command shows the options from the CICS file definition until
the first file for the data set is opened. If the options are obtained from the ICF
catalog when the first file is opened, the ICF catalog values are returned. The
128 CICS TS for z/OS 4.1: Recovery and Restart Guide