Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide

2–2 Compaq StorageWorks Data Replication Manager HSG80 ACS Version 8.5P Operations Guide
Remote Copy
Data Replication Manager uses the peer to peer remote copy function of the HSG80
controller to achieve data replication. HSG80 controller pairs at the initiator site are
connected to their partner HSG80 controller pairs at the target site. Remote copy sets are
created from units at the initiator and target sites. These remote copy sets are mirrors of
each other. As data is written to a unit at the initiator, it is mirrored to its remote copy set
partner unit at the target site.
The remote copy feature is intended not only for disaster recovery but to replicate data
from one storage subsystem or physical site to another subsystem or site. It also provides
methods of performing a backup at either the local or remote site. With remote copy, user
applications continue to run while data movement goes on in the background over a
separate interconnect. Data warehousing, continuous computing, and enterprise
applications all require remote copy capabilities. The remote copy feature is the major
component in the Compaq Storageworks Data Replication Manager solution.
Remote Copy Sets
A remote copy set is a bound set of two units, one located on the initiator and the other on
the target, for long distance mirroring. The units may be a single disk, or a storageset,
mirrorset or RAIDset. The local controller is designated as the Initiator. The initiator acts
as the director of the replication process. The corresponding remote controller is
designated as the Targe t. The target receives I/O requests from the initiator so as to
replicate the data at its location.
The ADD REMOTE_COPY_SETS RemoteCopySetName InitiatorUnitName
RemoteNodeName|TargetUnitName command creates a remote copy set and starts a
normalization copy to the target unit. During normalization, the controllers copy all data
from the initiator unit to the target unit.
Remote copy sets are created only at the initiator site. There can be up to 12 remote copy
sets per controller.