Whenever you need to increase or decrease the number of clusters for a multicluster CDS, you can perform nearly the same steps as you did to initially convert to multicluster usage. Follow the steps in Steps for converting to a multicluster control data set for converting to a multicluster control data set. As you next restart DFSMShsm, the new key boundaries that are used in your new clusters are dynamically determined and message ARC0087I is issued to prompt you to perform a CDS version backup. You should promptly back up the CDS because a CDS recovery requires that the last existing key boundaries as recorded in the journal match those in the CDS backup copy.