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

SETCACHE|||||||||||||||||||||||||||||||||||||||||||||Resetting All Cache and NVS Operating States to DefaultsSETCACHE REINITIALIZE performs the following:vvvResets all Storage Control cache and NVS operating states to the initialinstallation subsystem defaults (in addition all status tracks are reinitialized).Resets all status information to default state.Discards all modified tracks in the cache or NVS. All dual copy logical volumesare set to simplex state and all dual copy logical volumes are reset to simplex.To save the modified data, issue SETCACHE DESTAGE before issuingSETCACHE REINITIALIZE.Because of the nature of this command, all volumes in the subsystem must bevaried offline to all attached system images before the command is issued.Attention: Carefully consider the use of SETCACHE REINITIALIZE beforeissuing the command and ensure that all data has been destaged to DASD. Thiscommand resets all dual copy logical pairs to simplex state and resets theCCA/DDC pointers to their original state.Using Dual Copy to Migrate VolumesThe following steps show how to migrate data from one device to another withoutdisrupting the application. Separate procedures are provided for simplex volumesand duplex pair volumes.Notes:1. When you use dual copy to migrate volumes, remember that thecorrespondence between the original CCA and DDC addresses is switched andthat the Storage Control retains the updated CCA-to-DDC addresscorrespondence.Use the message response to the DEVSERV PATHS command to identify thecurrent CCA-to-DDC relationship.2. When you use dual copy to migrate from 3390 devices to RAMAC devices, aninvalid format 4 DSCB is created on the target device. Use ICKDSF to fix theformat 4 DSCB. See your IBM representative for the latest service level ofICKDSF that provides this function.Migrating Simplex VolumeThe following procedure is used to migrate simplex volumes, that is, volumes thatare not already part of a duplex pair. This procedure is valid for any two devicesqualified to be part of a duplex pair.1. Vary the target secondary volume offline to all attached systems.2. Issue SETCACHE SETSECONDARY.3. After the copy completes, issue SETCACHE SUSPENDPRIMARY.4. Issue SETCACHE RESETTOSIMPLEX.5. The original device is no longer in use. The application continues to access thesame UCB (MVS device address), but is using a different physical device.6. Proceed with required activities. Use ICKDSF to change the volser if required.Note: 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 to fixthe format 4 DSCB. See your IBM representative for the latest service levelof ICKDSF that provides this function.336 z/OS V1R6.0 DFSMS Access Method Services for Catalogs