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

Data Replication Manager Concepts 2–7
Figure 2–2. Association sets reside on the initiator controller pair
All members of an association set must be on the same controller to enforce cache
coherency. When members are added to an association set, they are moved to reside on the
same controller and will failover together.
Association set members can be either synchronous or asynchronous. This allows for
grouping only those members that will be using the write history log unit.
The ADD ASSOCIATIONS AssociationSetName RemoteCopySetName command adds an
association set with one member to the controller pair’s configuration. Use this command
on the node on which the initiator resides. Use the SET AssociationSetName ADD =
RemoteCopySetName command to add additional members.
Upon site failover, you must re-create the association sets and log units at the target
(failover) site, using the attributes that were set at the initiator site.
FAIL_ALL
If the FAIL_ALL switch is enabled and one member of the association set assumes the
failsafe locked condition, then all members of the association set assume the failsafe
locked condition. The failsafe locked condition prevents further host access.
IMPORTANT: This applies only to remote copy sets with Failsafe Error Mode enabled. Failsafe
Error Mode is enabled through the ERROR_MODE switch of the SET RemoteCopySets
command.
Unit Unit
LOCAL
RCS1
RCS2
Association
set 1
REMOTE
Unit Unit
CXO7069A