You might need to split the project VSAM data sets into multiple data sets because of security requirements, data set size, performance or changes in the way the project is being developed. By using multiple VSAM data sets in conjunction with flexible data set naming, cross-project support (for example, sharing common code) can be achieved.

The following steps make up the basic process for splitting project VSAM data sets:

1. Decide how you want to split the data sets. SCLM allows the VSAM data sets to be split on group boundaries.
2. Back up the data from the existing VSAM data sets for those groups using the new VSAM data sets. There are two ways to back up the data:
   1. You can use the SCLM export utility to export the contents of each group to the new data set. Because the Import utility deletes the contents of the export data set upon a successful completion of the import, you should make a backup of the export VSAM data sets using the IDCAMS reproduction utility (REPRO). By using this method, you do not need to update the contents of the PDS data sets. You only need to copy members from those groups that will be using the new VSAM data set. This method does not copy the audit records.
      Note: Using the REPRO function of the IDCAMS utility, you can split the audit data base at any point to create any number of smaller audit data bases. In order to use these smaller audit data bases, create alternate project definitions that specify the newly created audit data bases.
   2. You can use the IDCAMS REPRO utility to make a copy of each of the VSAM data sets used by the project. This method has the advantage of creating a backup of the project VSAM data sets. All records are copied to the new VSAM data set. While having the copies for all groups in the new VSAM data set is not a problem for SCLM, it does increase the size of the data set. These records can be deleted by setting up an alternate project definition that points only to the new VSAM data set and using the DELGROUP service to delete the groups that are not needed in that data set.
3. Make a backup copy of the project definition. This backup copy is needed to delete the data from the original VSAM data sets.
4. Update the project definition to add an FLMALTC macro for the new data sets and ALTC parameters on the groups that will be using those data sets.
5. Allocate the new VSAM data sets.
6. Assemble the new project definition.
7. Restore the data for the new VSAM data set from backup. How you do this depends on what method you used to back up the data:
   1. If you used the Export utility, use the Import utility to restore the data to the new VSAM data sets.
   2. If you used the IDCAMS REPRO utility, use the REPRO utility to restore the data. You can do this before assembling the new project definition because it does not use any SCLM services.
8. Test the new project definition. Here are some suggestions for testing the new project definition:
   • Edit a member at the modified group. Create a new member, and also edit an existing member.
   • Run a build from the modified group.
   • Promote from the modified group.
9. Delete data from the existing VSAM data set for those groups that reference the new VSAM data set. You can do this by using a backup copy of the old project definition and the Delete from Group utility for each group that was moved.

   If you used the method of promoting to a new group, this step is not needed.