z/OS V1R6.0 DFSMS Access Method Services for Catalogs

ALLOCATEvvRECFM(F) or RECFM(F B), then the logical record length is the length of theactual data fields.RECFM(U), omit the LRECL parameter.LRECL(nnnnnK) allows users of ANSI extended logical records and users ofQSAM “locate mode” to assign a K multiplier to the LRECL parameter. nnnnncan be a number within 1-16384. The K indicates that the value is multipliedby 1024.For variable-length spanned records (VS or VBS) processed by QSAM (locatemode) or BSAM, use LRECL (X) when the logical record exceeds 32,756 bytes.For PDSEs, the meaning of LRECL depends upon the data set record format:vvFixed Format Records. For PDSEs opened for output, the logical recordlength (LRECL) defines the record size for the newly created members. Youcannot override the data set control block (DSCB) (LRECL); an attempt to doso will result in an error.Variable Format Records. The LRECL is the maximum record length forlogical records that are contained in members of the PDSE.v Undefined Format Records. The LRECL is the maximum record length forrecords that are contained in members of the PDSEs.MGMTCLAS(management-class-name)For SMS-managed data sets: This is the 1-to-8 character name of the managementclass for a new data set. When possible, do not use MGMTCLAS. Allow it todefault through the ACS routines.After the system allocates the data set, attributes in the management classdefine:vvThe migration of the data set. This includes migration both from primarystorage to migration storage, and from one migration level to another in ahierarchical migration scheme.The backup of the data set. This includes frequency of backup, number ofversions, and retention criteria for backup versions.If SMS is not active, the system checks the syntax and ignores the MGMTCLASparameter.MAXVOL(count)This is the maximum number (1-255) of volumes upon which a data set canreside. This number corresponds to the count field on the VOLUME parameterin JCL. Use this to override the volume count attribute defined in the dataclass of the data set.If VOLUME and PRIVATE parameters are not given, and MAXVOL exceedsUCOUNT, the system removes no volumes when all the mounted volumeshave been used, causing abnormal termination of your job. If PRIVATE isgiven, the system removes one of the volumes and mounts another volume inits place to continue processing.MAXVOL overrides any volume count in the data class (DATACLAS) of thedata set.Your user attribute data set (UADS) must contain the MOUNT attribute. Use ofthis parameter implies PRIVATE.NEWThis creates a data set. For new partitioned data sets, you must use the DIRChapter 4. ALLOCATE 41