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

SETCACHE||||||||||||||||||||||||||||||||||||||||||||||SETSECONDARY(devid)specifies that a dual copy (duplex) pair is to be established. The secondaryvolume must be offline and is identified by its devid (devid is the MVS devicenumber). DASD fast write and caching status of the primary volume aremaintained for the duplex pair.Abbreviation: SSECNotes:1. This parameter is not supported for the ESS.2. With this parameter, the JCL JOB statement should include ’TIME=1440’.3. This parameter may be used in conjunction with COPY (with or withoutPACE) or NOCOPY.4. During the process of establishing a duplex pair, caching for the primaryvolume is temporarily deactivated.5. When you use dual copy to migrate from 3390 devices to RAMAC devices,an invalid format 4 DSCB is created on the target device. Use ICKDSF tofix the format 4 DSCB. See your IBM representative for the latest servicelevel of ICKDSF that provides this function.Device level caching, for both primary and secondary devices, is set to off toforce data destaging. It is set back to on, automatically by software, after thedual copy operation completes.The software can be overridden by IDCAMS allowing cache to be set on afterthe establishment of a duplex pair has been initiated (verify with a DEVSERVcommand that status is pending for primary device before setting device cacheto on).SUSPENDPRIMARYsuspends the primary volume of a duplex pair. The subsystem swaps theprimary and secondary volumes of the duplex pair. The suspended device isthe secondary address. DASD fast write status and caching status aremaintained.Abbreviation: SUSPRI or SPPRINote: This parameter is not supported for the ESS.SUSPENDSECONDARYsuspends the secondary volume of a duplex pair. DASD fast write status andcaching status are maintained.Abbreviation: SUSSEC or SPSECNote: This parameter is not supported for the ESS.RESETTODUPLEXestablishes a duplex pair from a suspended duplex pair. The subsystem alwaysattempts to match channel connection addresses (CCAs) and director-to-deviceconnection (DDC) addresses, and swaps the devices after synchronization if aswap would result in a match. If the pair is swapped, all data in the cache isinvalidated. DASD fast write status and caching status are maintained.Abbreviation: RESETDUP or REDUPNotes:1. This parameter is not supported for the ESS.2. With this parameter, the JCL JOB statement should include ’TIME=1440’.Chapter 31. SETCACHE 331