Quantum QXS G2 Series, Hardware Installation And Maintenance Manual

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Installation 99
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 different networks. As you consider the
physical connections of your system—specifically connections for replication—keep several important
points in mind:
• Ensure that controllers have connectivity between systems, whether the destination system is
co-located or remotely located.
• Qualified Converged Network Controller options can be used for host I/O or replication, or both.
• The storage system does not provide for specific assignment of ports for replication. However, this
can be accomplished using virtual LANs for iSCSI and zones for FC, or by using physically separate
infrastructure. Refer to Multiple Servers/Single Same Network on page 100 for additional
information.
• For remote replication, ensure that all ports assigned for replication are able to communicate
appropriately with the replication system (see the QXS G2 CLI Reference Guide for more
information): by using the query peer-connection CLI command.
• Allow a sufficient number of ports to perform replication.
• This permits the system to balance the load across those ports as I/O demands rise and fall.
• If some of the volumes replicated are owned by controller A and others are owned by
controller B, then allow at least one port for replication on each controller module—and
possibly more than one port per controller module—depending on replication traffic load.
• For the sake of system security, do not unnecessarily expose the controller module network port to
an external network connection.
Conceptual cabling examples are provided addressing cabling on the same network and cabling
relative to different networks.
IMPORTANT: The replication feature must be licensed on all systems configured for replication, and
the controller module firmware must be compatible on all systems used for replication. See the topic
about licensed features in the
QXS G2 Disk Management Utility User Guide
.
Cabling for Replication
The following sections show example replication configurations for CNC-based RAID chassis.
NOTE: Simplified versions of RAID chassis are used in cabling illustrations to show host ports used
for I/O or replication, given that only the external connectors used in the host interface ports differ.
• Replication supports FC and iSCSI host interface protocols.
• The 2U chassis rear panel represents the 2U12/2U24 RAID chassis (4-port) models.
• The 5U chassis rear panel represents the 5U84 RAID chassis (4-port) models.
• Host ports used for replication must use the same protocol (either FC or iSCSI).
• Blue cables show I/O traffic and green cables show replication traffic.
Once the CNC-based systems are physically cabled, see the
QXS G2 Disk Management Utility User
Guide
or online help for information about configuring, provisioning, and using the optional
replication feature with out-of-band management.