The virtual lookaside facility (VLF) enables an authorized program to store named objects in virtual storage that is managed by VLF and to retrieve these objects by name on behalf of users in multiple address spaces. VLF is designed primarily to improve performance by retrieving frequently used objects from virtual storage rather than performing repetitive I/O operations from DASD. Certain IBM® products or components such RACF® use VLF as an alternate way to access data.

If you are using the virtual lookaside facility (VLF), update the VLF parmlib member, COFVLFxx. Add CLASS and EMAJ statements to activate a RACF performance option for z/OS UNIX. The following example shows the added statements in an example of a COFVLF33 member.

CLASS NAME(IRRGMAP)          /* GMAP table for z/OS UNIX System Services */
     EMAJ(GMAP)              /* Major name = GMAP                        */
     CLASS NAME(IRRUMAP)     /* UMAP table for z/OS UNIX System Services */
     EMAJ(UMAP)              /* Major name = UMAP                        */ 
                                          

START VLF,SUB=MSTR,NN=33

For information about caching UIDs and GIDs, see Caching RACF user and group information in VLF.