Dot Hill Systems 4524 - CNC Ports and Replication; Single-Controller Configuration; Dual-Controller Configuration; Connecting Two Storage Systems for Replication: One Server;Two Switches;One Location

70 Connecting hosts
CNC ports and replication
CNC controller modules can use qualified SFP options of the same type, or they can use a combination of
qualified SFP options supporting different host interface protocols. If you use a combination of different
protocols, then CNC ports 0 and 1 must be set to FC (either both16 Gbit/s or both 8 Gbit/s), and CNC
ports 2 and 3 must be set to iSCSI (either both 10GbE or both 1 Gbit/s).
In linear storage environments [RAIDar (v2)], each CNC port can perform I/O or replication. In
combination environments, one interface—for example FC—might be used for I/O, and the other interface
type—10GbE or 1 Gb iSCSI—might be used for replication. In virtual storage environments [SMC (v3)],
each CNC port can perform I/O, but replication traffic is supported by iSCSI host interface ports (either
both 10GbE or both 1 Gbit/s).
Single-controller configuration
One server/single network/two switches
The diagrams below shows the rear panel of two controller enclosures with both I/O and replication
occurring on the same network. Each enclosure is equipped with a single controller module.
Figure 71 Connecting two storage systems for replication: one server/two switches/one location
CNC ports used for replication must be connected to at least one switch. For optimal protection, use two
switches, with one CNC replication port from each controller connected to the first switch, and the other
CNC replication port from each controller connected to the second switch. Using two switches in tandem
avoids the potential single point of failure inherent to using a single switch.
Dual-controller configuration
Each of the following diagrams show the rear panel of two 4004 Series controller enclosures equipped
with dual-controller modules.
IMPORTANT: Whereas linear storage supports FC and iSCSI host interface protocols for replication, virtual
storage supports iSCSI host interface protocol for replication. Both linear and virtual storage support all
qualified CNC options for host connection.
6Gb/s
S
S
A
6Gb/s
S
S
A
4824/4834/4844 controller enclosure
I/O switch
(replication)
Switch
To host server
4824/4834/4844 controller enclosure
IOM blank IOM blank