Using SMS DATACLAS RLSCFCACHE: VSAM RLS allows multiple levels of coupling facility caching for XCF cache structures that are defined in the active SMS configuration. The value of the SMS DATACLAS RLSCFCACHE keyword determines the level of CF caching. Specify new DIRONLY parameter to DATACLAS RLSCFCACHE to specify that RLS not cache the data or index part of the VSAM data set in the coupling facility cache structure. In this case, RLS will use the XCF cache structure to keep track of data that resides in permanent storage (DASD) and in local storage but is not stored in the cache structure itself. This lets each SMSVSAM in the sysplex keep track of whether locally cached copies of the data are valid and contain the latest changes without actually writing any data to the cache structure. See Using VSAM Record-Level Sharing in z/OS DFSMS Using Data Sets.
Using ISMF: To specify that RLS not cache data or index parts of the VSAM data set in the coupling facility cache structure, specify new DIRONLY parameter in the RLS CF Cache Value data class attribute in ISMF. In this case, RLS will use the XCF cache structure to keep track of data that resides in permanent storage (DASD) and in local storage but is not stored in the cache structure itself. This lets each SMSVSAM in the sysplex keep track of whether locally cached copies of the data are valid and contain the latest changes without actually writing any data to the cache structure. See Defining Shareoptions and RLS attributes for data class in z/OS DFSMSdfp Storage Administration.