You must complete some tasks and make some decisions before you start using CICSVR. To implement a backup and recovery strategy for your organization, using CICSVR, consider these points:
Establish procedures to produce regular backup copies of the VSAM spheres that you want to protect. Schedule a regular time to back up your VSAM spheres. If you change the physical characteristics of a VSAM sphere, such as the control interval (CI) size or the length or location of a key field, make a new backup of the VSAM sphere. This ensures that the latest attributes are preserved if you need to restore the VSAM sphere later.
If your CICS® regions are operating only for a certain number of hours in each day, make backups of your VSAM spheres outside these hours, when the spheres are unavailable to users. Consider using BWO and the concurrent copy function to make VSAM spheres continuously available. To take full advantage of CICSVR recovery control, use DFSMShsm to make your backups. CICSVR automatically restores the DFSMShsm backup before starting the recovery.
The CICS log manager uses the services of the MVS™ system logger to write CICS log and journal data to MVS log streams. A log stream is a sequence of data blocks, with each log stream identified by its own log stream identifier--the log stream name (LSN). The CICS system log, forward recovery logs (including the log of logs), autojournals, and user journals map onto specific MVS log streams. CICS forward recovery logs, user journals, and autojournals are referred to as general logs, to distinguish them from system logs.
Both the MVS system logger and CICS log manager have extensive recovery procedures to prevent errors from causing the loss of your VSAM data. For CICS Transaction Server, CICSVR provides support only for the log of logs and forward recovery logs. You cannot use CICSVR to perform forward recovery from autojournals written by CICS Transaction Server regions. However, for earlier releases of CICS, CICSVR continues to support system logs and autojournals.
There are different ways that
you might use the log stream copy utility DWWLC.
To avoid the possibility of loosing records, ensure that all VSAM data sets that use the log stream are closed and all remaining log records have been forced to the MVS log stream before running the logstream copy job. See the CICSVR Implementation Guide for additional information about the steps that should be followed if you plan to delete the log stream after it is copied.
For more information about defining CICS logs and journals, see the CICS System Definition Guide.
You will probably want to be able to forward recover all VSAM spheres that are defined as CICS files. Of course, data sets that are read-only or browse-only do not need forward recovery, but it is wise to back them up regularly in case they become unusable.
To use CICSVR to recover your data, specify the required recovery attributes when you define your files to CICS. For details about the recovery attributes required by CICSVR, see the IBM® CICS VSAM Recovery MVS/ESA Implementation Guide. If your files are accessed in RLS mode, you define the recovery attributes with the data set definition in the ICF catalog. For more information about RLS recovery definitions, see the DFSMS/MVS Access Method Services for ICF, SC26-4906.
Five exits are available for use with CICSVR:
Except for the ESDS delete exit, the use of CICSVR exits is optional.
For more information about the CICSVR exits, see the IBM CICS VSAM Recovery MVS/ESA Implementation Guide.
When you are ready to use CICSVR, define a concise set of operational procedures for use if VSAM data is lost or damaged. Document the procedures required to recover from all error situations concerning CICS VSAM data. Here are some topics to consider when designing your operational procedures: