z/VM: CP Planning and Administration - z/VM - IBM

CSELVOL INCLUDEUsageNotesdefined as volid within the above syntax diagram. The value of nn should be inthe range of 0 to 64, but it cannot be 0 if CYL=0. The default is 1. See UsageNote 5.For ECKD capable CKD devices multiple tracks are used. The number of tracksused for ECKD capable CKD devices depends on the number of cylinders onthe volume. The value specified in TRK=nn is not used for an ECKD capableCKD device.RECL=nnnnndefines the number of cylinders made available for CSE use. This value shouldbe at least equal to the number of cylinders on the volume. If it is smaller thanthe number of cylinders on the volume, links to minidisks starting on a cylinderwith a number higher than nnnnn are denied. The value of nnnnn should be inthe range of 203 to the maximum cylinder on the volume. Table 34 on page 652shows the map record defaults for each device type. See Usage Note 5.For CKD devices nnnnn also defines the record length of the map records. Onthese devices one byte in the map record corresponds to one cylinder. Allcylinders are mapped in one physical record per system. On ECKD capableCKD devices there may be several physical records per system. One byte inthe map record corresponds to two cylinders. Each physical record is 256 bytesand maps 512 cylinders. The number of physical records needed depends onthe number of cylinders made available to CSE. See Usage Note 5.RECS=nndefines the number of map records on the CSE track. The variable nn shouldbe at least equal to the number of systems that share the volume. If nn issmaller than the number of sharing systems, then all links to minidisks on thisvolume are denied. It is recommended that you use as many records as can fiton one track. Refer to Table 34 on page 652 for the default values. See UsageNote 5.1. You can specify as many CSELVOL INCLUDE macros as you need. As manyCSELVOL macros as are required may be specified.2. All the CSELVOL INCLUDE macros must precede any CSELVOL EXCLUDEmacros.3. If CSELVOL INCLUDE or EXCLUDE macros are not specified, all DASDvolumes are included in cross system link.4. If CSELVOL INCLUDE macros are coded in HCPSYS, volumes not specified inthe CSELVOL INCLUDE statements are not included in cross system link.5. Although the CSELVOL INCLUDE macro lets you change the definitions ofcylinder, track, record length, and map records for the CSE track, we do notrecommend that you do so. Leaving the defaults alone enables you to providelink support for new devices with new geometries, should that support becomenecessary in the future.Attention: Current upper limits may exceed capacities of present devices andcause errors when attempting to access beyond a particular device limit.Therefore, any change of defaults should be done with caution.Appendix B. Defining Your System (HCPSYS Macroinstructions) 651