FDRPAS and FDRPASVM overview

z/VM system requirements

We recommend that your z/VM system be at the latest Recommended Service Upgrade (RSU) service level. See the z/VM web page with the latest RSU for each supported z/VM release: http://www.vm.ibm.com/service/rsu/

FDRPAS and FDRPASVM overview

FDRPAS on z/OS is used to move z/OS and z/VM DASD volumes non-disruptively from one DASD volume to another, and to create non-disruptive point-in-time backups of DASD volumes.

FDRPAS on z/OS in conjunction with FDRPASVM on z/VM allows organizations to: 

• Swap DASD volumes from their current locations to new DASD hardware
• Move DASD volumes within the installation for load balancing
• Create point-in-time backups of DASD volumes
• Create duplex (mirrored) copies of DASD volumes
• Do this volume movement without interrupting any system activity
• Do this volume movement during normal system operations
• Swap shared DASD on all sharing systems simultaneously
• Swap many DASD volumes concurrently

FDRPASVM benefits

The following are some of the benefits of FDRPASVM:

• The operating system, application jobs, online systems, and users should not be aware that FDRPASVM is swapping DASD volumes to new DASD devices. A 24x7 installation, with no window for major re-configurations and hardware changes, can install and activate new DASD hardware.
• Even installations that do have dedicated maintenance windows can use FDRPASVM to swap to new DASD hardware during normal business hours. No matter how long your maintenance window is, it is not long enough to move the terabytes of data in most installations. FDRPASVM removes that limitation.
• FDRPASVM can be used for load balancing within your existing DASD hardware.
• FDRPASVM can create point-in-time backups without special hardware features.
•  It can create duplex (mirrored) copies of volumes, between control units from different vendors, without special hardware connections. These copies can be in local or remote subsystems.

FDRPASVM supports the hardware described in FDRPAS overview.

FDRPAS requirements

FDRPAS on z/OS must be installed and configured to work in conjunction with FDRPASVM. The minimum level of FDRPAS on z/OS to support FDRPASVM is version 5.4 level 83.

FDRPASVM overview

FDRPASVM operation

The following are the high-level steps involved in swapping volumes:

1. The FDRPASVM service machine receives a SWAP request via IUCV from the user command module. The FDRPASVM service machine main thread attaches eligible target devices to the service machine and creates a single volume watch thread that monitors all the targets.
2. The FDRPAS main swap task, running on z/OS, copies a z/VM source volume to a z/VM target volume.
3. The FDRPASVM “intercepts” are installed to the source volumes on z/VM to monitor any changes to source volume.
4. The z/OS Main SWAP task copies the entire source volume to the target volume.
5. Any changes detected by the FDRPASVM volume swap thread are made known to the z/OS Main SWAP task to recopy these tracks. This continues until the HyperSwap command is performed.
6. Once all tracks are copied from the source volume to the target volume and any changes have also been copied, the SWAP can be performed and the target volume becomes the new volume to the z/VM applications.
7. The FDRPASVM intercepts are removed.