PPRC, available on all supported z/OS® releases, is a hardware solution to the problem of accurate and rapid disaster recovery, and also provides a workload migration solution. It is designed to provide data transfer synchronously and asynchronously.
Synchronous PPRC is designed to provide real-time mirroring of
logical volumes within an ESS or between two ESSs. The sites using synchronous PPRC
must conform to the following conditions:
- Need the recovery system to always be fully current with the primary system
- Can accept some performance impact to application write I/O operations at the primary location
- Can accept typical write overhead plus 1ms per km impact.
PPRC extended distance is designed for those sites that
conform to the following conditions:
- Need a disaster recovery solution with a recovery point object (RPO) of many hours, or even several days.
- Have the primary and recovery storage control sites separated by very long distances beyond those supported for synchronous PPRC.
- Need the flexibility to use both synchronous and asynchronous data transfers, especially when bandwidth restrictions are a consideration.
Figure 1 presents an overview of the PPRC option of remote copy, based on a disaster recovery need. The workload (or DASD) migration configuration is basically the same, except that the "recovery site" would be considered the "migration target."
Figure 1. PPRC overview