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

ALLOCATEThe system copies these attributes only if SMS is not active:BLKSIZE Block sizeEXPDT Data set expiration dateOPTCD Optional services code (for ISAM data sets only)VSEQ Volume sequence number.You can still use the LIKE parameter even if you do not have an existing dataset with the exact attributes you want to assign to a new data set. You can useALLOCATE attributes to override any model data set attributes you do notwant assigned to the new data set.When you use this:vvvvvvvLIKE must be used with the NEW parameter; it cannot be used with OLD,SHR, or MOD.Use LIKE with the DATASET parameter; it cannot be used with FILE.Only one dsname can be given in the DATASET parameter.The system does not copy the block size from the model data set when SMSis active. If you do not show a block size in the ALLOCATE command, thesystem determines an optimal block size to assign to the data set.When SMS is active, attributes copied from the model data set overrideattributes from the data class.If you allocate the new data set with a member name (indicating apartitioned data set), the system prompts you for directory blocks unlessthat quantity is either shown in the ALLOCATE command or defaulted fromthe LIKE data set.If the new data set name is indicated with a member name, but the modeldata set is sequential and you have not given the quantity for directoryblocks, you are prompted for directory blocks.If you define the directory value as zero and the model data set is a PDS, thesystem allocates the new data set as a sequential data set.The LIKE, REFDD, and USING operands are mutually exclusive. Refer to z/OSTSO/E Command Reference for additional information on the USING operand.LIMCT(search-number)This is the number of blocks or tracks that the system should search for ablock or available space. The number must not exceed 32760.LRECL({logical-record-length|(nnnnnK|X)})This is the length, in bytes, of the largest logical record in the data set. Youmust define this parameter for data sets that consist of either fixed-length orvariable-length records.Use the DATACLAS parameter in place of LRECL to assign the logical recordlength. If SMS is active and you use LRECL, the system determines the blocksize.If the data set contains undefined-length records, omit LRECL.The logical record length must be consistent with the requirements of theRECFM parameter and must not exceed the block size (BLKSIZE parameter),except for variable–length spanned records. If you use:vRECFM(V) or RECFM(V B), then the logical record length is the sum of thelength of the actual data fields plus four bytes for a record descriptor word.40 z/OS V1R6.0 DFSMS Access Method Services for Catalogs