Comparison Of Copy Services Features - IBM DS8900F Introduction And Planning Manual

resource groups, see topics about resource groups. For specific DS CLI commands used to implement
resource groups, see the IBM DS8000 Command-Line Interface User's Guide.

Comparison of Copy Services features

The features of the Copy Services aid with planning for a disaster.
Table 17 on page 52 provides a brief summary of the characteristics of the Copy Services features that
are available for the storage system.
Table 17. Comparison of features
Feature
Multiple Target PPRC
Metro/Global Mirror
Metro Mirror
Global Copy
Global Mirror
z/OS Global Mirror
52 IBM DS8900F: DS8900F Introduction and Planning Guide
Description
Synchronous and
asynchronous
replication
Three-site, long distance
disaster recovery
replication
Synchronous data copy
at a distance
Continuous copy without
data consistency
Asynchronous copy
Asynchronous copy
controlled by IBM Z host
software
Advantages
Mirrors data from a
single primary site to
two secondary sites
simultaneously.
A backup site is
maintained regardless of
which one of the sites is
lost.
No data loss, rapid
recovery time for
distances up to 300 km.
Nearly unlimited
distance, suitable for
data migration, only
limited by network and
channel extenders
capabilities.
Nearly unlimited
distance, scalable, and
low RPO. The RPO is the
time needed to recover
from a disaster; that is,
the total system
downtime.
Nearly unlimited
distance, highly
scalable, and very low
RPO.
Considerations
Disaster recovery
scenarios depend on
support from controlling
software such as
Geographically
Dispersed Parallel
Sysplex (GDPS) and IBM
Copy Services Manager
Recovery point objective
(RPO) might grow if
bandwidth capability is
exceeded.
Slight performance
impact.
Copy is normally fuzzy
but can be made
consistent through
synchronization.
RPO might grow when
link bandwidth
capability is exceeded.
Additional host server
hardware and software
is required. The RPO
might grow if bandwidth
capability is exceeded or
host performance might
be impacted.