ACB   MACRF=({NSR|LSR|GSR},...),...

NSR, the default, indicates the data set does not use shared resources. LSR indicates it uses the local resource pool. GSR indicates it uses the global resource pool.

If the VSAM control blocks and data buffers reside above 16 MB, RMODE31=ALL must be specified in the ACB before OPEN is issued. If the OPEN parameter list or the VSAM ACB resides above 16 MB, the MODE=31 parameter of the OPEN macro must also be coded.

When an ACB indicates LSR or GSR, VSAM ignores its BSTRNO, BUFNI, BUFND, BUFSP, and STRNO parameters because VSAM will use the existing resource pool for the resources associated with these parameters.

To connect LSR pools with a SHRPOOL identification number other than SHRPOOL=0, you must use the SHRPOOL parameter of the ACB macro to indicate which LSR pool you are connecting.

If more than one ACB is opened for LSR processing of the same data set, the LSR pool identified by the SHRPOOL parameter for the first ACB will be used for all subsequent ACBs.

For a data set described by an ACB with MACRF=GSR, the ACB and all related RPLs, EXLSTs, ECBs, and data areas must be in the common area of virtual storage with the same protection key as the resource pool.