Duplexing structures

Duplexed structures are duplicate structures for the same area.

Duplexing allows you to have dual structure support for your VSO DEDB areas, which helps to ensure the availability and recoverability of your data.

Structure duplexing can be either IMS-managed or system-managed. With IMS-managed duplexing, you must define both the primary and the secondary structures in DBRC and in the z/OS® coupling facility resource management (CFRM) policy. When you use system-managed duplexing, you have to define only the primary structure. The duplexing operation is transparent to you, except that you need to request duplex mode in your CFRM policy and allocate additional resources for a secondary structure instance.

VSO multi-area structures require the use of system-managed duplexing.