Administrator Guide

Requirement Description
• Asynchronous replication: Version 5.5 or later
Storage Center license The source and destination Storage Centers must be licensed
for Remote Instant Snapshot.
Storage Manager conguration The source and destination storage system must be added to
Storage Manager Data Collector.
NOTE: Replications cannot be created or managed when
the Dell Storage Manager Client is directly connected to
a
Storage Center.
Storage Center communication The storage systems must be connected using Fibre Channel or
iSCSI, and each storage system must be dened on the other
storage system.
QoS Denition On the source Storage Center, a quality of service (QoS)
denition must be set up for the replication.
Related link
Add a Storage Center
Creating and Managing Replication Quality of Service Denitions
Connecting to Remote Storage Centers
Replication Behavior When a Destination Volume Fails
When the destination volume becomes unavailable, each replication type behaves slightly dierently. The replication types also
recover dierently when the destination volume comes back online.
Scenario
Asynchronous Replication Synchronous Replication
Destination volume is unavailable Allows IO requests to the source volume
• High Consistency mode: Fails IO
requests to the source volume
• High Availability mode: Allows IO
requests to the source volume
Destination volume comes back online Resumes transferring snapshots from the
source volume and re-copies Active
Snapshot data (if enabled)
• High Consistency mode: Resumes
accepting IO requests to the source
volume
• High Availability mode: Resumes
transferring snapshots from the
source volume and copies the Active
Snapshot data that was missed while
the destination volume was unavailable
Replicating a Single Volume to Multiple Destinations
Multiple replications can be congured for a single source volume. Two topologies are supported:
• Mixed mode: A source volume is replicated in parallel to multiple Storage Centers.
Example: Two replications are created in parallel:
– Replication 1: Storage Center A → Storage Center B
– Replication 2: Storage Center A → Storage Center C
• Cascade mode: A source volume is replicated in series to multiple Storage Centers.
Example: Two replications are created in series:
– Replication 1: Storage Center A → Storage Center B
– Replication 2: Storage Center B → Storage Center C
Storage Center Replications and Live Volumes
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