Port Requirements; Planning Consistency Groups; Consistency Group Requirements - HP StorageWorks P9000 User Manual

operations. When you want to copy data from secondary system to primary system, RCU
target ports must be configured also on the primary system.
External port: Required for External Storage copy operations. This port is not used for
Continuous Access Synchronous copy operations. This port can be changed to a target,
initiator, or RCU target port.
Initiator/external port: This setting shows the combination of ports that have an initiator port
and an external port attribute. Only a port that has an initiator port attribute within these ports
can be used for Continuous Access Synchronous. This attribute cannot be changed by the
Continuous Access Synchronous software. For details on the port to which an initiator/external
mix mode is set, see the HP StorageWorks P9000 External Storage for Open and Mainframe
Systems User Guide.

Port requirements

Ports set up for Continuous Access Synchronous operations have the following maximum and
minimum requirements:
One initiator port can be connected to a maximum of 64 RCU target ports.
One secondary system port can be connected to a maximum of 16 ports on a primary system.
The number of logical paths that can be specified does not depend on the number of ports
configured for Continuous Access Synchronous.

Planning consistency groups

With consistency groups, you perform Continuous Access Synchronous operations on a group of
pairs that are within the same primary and secondary systems. You assign pairs to a consistency
group during the paircreate operation. Consistency groups insure that pairs in the group are kept
in a consistent status. They also allow you to perform an operation on all the pairs at the same
time.
You determine which pairs to include in a consistency group. This should be based on your criteria
for keeping status consistent across a particular group of pairs, and for performing specific
operations at the same time on the pairs.
For information on creating pairs and assigning them to consistency groups using RAID
Manager, see the HP StorageWorks P9000 RAID Manager User Guide.
With Remote Web Console, only one consistency group is supported. New pairs are assigned
to consistency group 127 automatically when you turn function switch 30 ON, create the pair
or pairs, then turn function switch 30 OFF.

Consistency group requirements

Consistency groups used with Continuous Access Synchronous pairs have the following requirements:
A Continuous Access Synchronous pair can be assigned to only one consistency group.
Use 8,192 pairs or less in one consistency group.
Between one MCU and one RCU, you can have up to 128 consistency groups.
Continuous Access Synchronous pairs cannot be in the same consistency group as Continuous
Access Synchronous for z/OS pairs.
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