Administrator Guide

data block by block, and transmitting only blocks that dier. While deduplication can be resource-intensive, it is useful when replicating
volumes over lower bandwidth WAN links.
Replication Requirements
To replicate a volume from one Storage Center to another Storage Center, the requirements listed in the following table must be met.
Requirement Description
Storage Center license The source and destination Storage Centers must be licensed for
Remote Instant Replay (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 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 links
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.
Storage Center Replications and Live Volumes
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