HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

This is shown in the following table indicates the following:

• Italicized/Gray background: Cnt Ac-S and Cnt Ac-S Z pair status before the split operation

on the consistency group

• Regular font: Status after the split operation

Cnt Ac-S Z pairsPair statuses

All = SuspendSome = Duplex,

some = Suspend

All

Cnt Ac-S: PSUSCnt Ac-S: PSUSCnt Ac-S: PSUSAll = PAIR

Cnt Ac-S Z: SuspendCnt Ac-S Z: SuspendCnt Ac-S Z: Suspend

Cnt Ac-S: PSUSCnt Ac-S: PSUSCnt Ac-S: PSUSSome = PAIR,Cnt

Ac-S

Cnt Ac-S Z: SuspendCnt Ac-S Z: SuspendCnt Ac-S Z: Suspendsome = PSUS

Cnt

Ac-S

pairs

Cnt Ac-S: PSUSCnt Ac-S: PSUSCnt Ac-S: PSUSAll = PSUS

Cnt Ac-S Z: SuspendCnt Ac-S Z:Cnt Ac-S Z:

- RAID Manager:

Duplex/Suspend

- RAID Manager: Duplex

- BCM: Suspend

Error reporting communications

Error reporting communications (ERC) transfers information between host processors at the main

and remote sites. It is a critical component of a disaster recovery effort.

You can configure ERC using channel to channel communications, NetView technology, or other

inter-connection technologies depending on your installation requirements and standards. Cnt Ac-S

Z does not provide ERC between the main and remote sites.

• When Cnt Ac-S Z is used as a disaster recovery tool, ERC is required to ensure effective

recovery operations.

• When Cnt Ac-S Z is used as a data migration tool, ERC is recommended.

• When a pair is suspended due to an error condition, the main system generates sense

information that results in an IEA491E system console message. This information should be

transferred to the remote site using ERC for effective disaster detection and recovery.

Data path requirements and configurations

A data path must be designed to adequately manage all possible amounts of data that could be

generated by the host and sent to the P-VOL and S-VOL. This topic provides requirements and

planning considerations for the following key elements of the data path:

• “Bandwidth requirements” (page 46)

• “Fibre Channel requirements” (page 47)

• “Supported data path configurations” (page 47)

• “Ports” (page 49)

Bandwidth requirements

Sufficient bandwidth must be present to handle data transfer of all workload levels. The amount

of bandwidth required for your Cnt Ac-S Z system is based on the amount of I/O sent from the

host to the main volume. You determine required bandwidth by measuring write-workload. Workload

46 Planning for Continuous Access Synchronous Z