The GENVSAMCOMPNAMES specified setting overrides the SETSYS DSBACKUP(GENVSAMCOMPNAMES) setting. If GVCN=YES is specified, and newdsname represents a VSAM base cluster that is either migrated or uncataloged, DFSMShsm will process the request, and default names will be assigned to the VSAM data and index components (.data and .index). If GVCN=NO is specified, and newdsname represents a VSAM base cluster that is either migrated or uncataloged, the HBACKDS command will fail, as DFSMShsm is unable to assign the proper names to the data and index components. If the newdsname is uncataloged or has been migrated outside of DFSMShsm, and the data set to be backed up is VSAM and has an associated AIX/PATH, the SPHERE(NO) keyword must be specified on the command. If GVCN is specified and the data set to back up is non-VSAM or is VSAM and is cataloged and not migrated, the GVCN keyword will be ignored.