Chapter 3: Connecting Hosts
Connect Two Storage Systems to Replicate Volumes
QX and QXS Setup Guide
109
Note:
Connections to this device must be made with shielded cables grounded at both ends with
metallic RFI/EMI connector hoods in order to maintain compliance with NEBS and FCC Rules and
Regulations, see the
Quantum Product Regulatory Compliance and Safety
document.
Connect Two Storage Systems to Replicate
Volumes
Replication is a licensed feature for disaster recovery, providing access to either of the following software
product versions:
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V3 disk management utility supports replication for virtual storage environments.
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V2 disk management utility supports replication for linear storage environments.
Note:
These two replication models are mutually exclusive to one another. Choose the method that
applies to your storage system. For more information, see replication topics in the disk management
utility.
The replication feature performs asynchronous replication of block-level data from a volume in a primary
system to a volume in a secondary system by creating an internal snapshot of the primary volume, and
copying the snapshot data to the secondary system via FC (linear storage only) or iSCSI links.
The two associated standard volumes form a replication set, and only the primary volume (source of data)
can be mapped for access by a server. Both systems must be licensed to use the replication feature, and
must be connected through switches to the same fabric or network (i.e., no direct attach). The server
accessing the replication set need only be connected to the primary system. If the primary system goes
offline, a connected server can access the replicated data from the secondary system.
Replication configuration possibilities are many, and can be cabled—in switch attach fashion—to support
the CNC-based systems on the same network, or on physically-split networks (SAS systems do not support
replication). As you consider the physical connections of your system—specifically connections for
replication—keep several important points in mind:
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Ensure that controllers have connectivity between systems, whether local or remote.
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Whereas linear storage supports FC and iSCSI host interface ports for replication, virtual storage
supports iSCSI host interface ports for replication. Both linear and virtual storage support all qualified
CNC options for host connection.
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If using the RAIDar (v2) user interface, be sure of the desired link type before creating the linear
replication set, because you cannot change the replication link type after creating the replication set.
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Assign specific ports for replication whenever possible. By specifically assigning ports available for
replication, you free the controller from scanning and assigning the ports at the time replication is
performed.
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Ensure that all ports assigned for replication are able to communicate appropriately with the replication
system (see the CLI Reference Guide for more information):
