Multi-Port Mirrored Single Host-Dual Connection - NexStor 4900F Series User Manual

Chapter 2 - Topologies and Operating Modes

Multi-Port Mirrored Single Host-Dual Connection

This Multi-Port Mirrored topology provides an active-active RAID storage solution
for single host systems with dual Fibre ports where fault-tolerant RAID disk
subsystem storage is required. It has several advantages: redundant active-active
controllers, and transparent failover and failback operations, Logical Drive (LUN)
isolation (LUNs appear only once to the host OS), and dual connections for
higher performance independent access to assigned logical drive.
It has two disadvantages which are the host HBA and the single fibre loop which
are single points of failure.
In this topology the Host I/O card switch 1, 2, and 6 are set to the "Up" position.
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Multi-Port Mirrored Single Host-Dual Connection
Host/Server (Node A)
FC HBA 1
H1
Right Host I/O Card
Failover
Circuit
Port 0 (P0)
Active
Controller 0 (C0)
Duplex Mode Logical View - Multi-Port Mirrored Single Host-Dual Connection
Switch 1 sets the bus speed mode on the Host I/O card to 2 GB/sec.
Switch 2 configures the enclosure for the RAID Controller.
Switch 6 enables automatic internal hub failover during a controller failure.
FC HBA 2
H0
Port 1 (P1)
Active
H1 H0
Left Host I/O Card
Failover
Circuit
Port 0 (P0) Port 1 (P1)
Active Active
Controller 1 (C1)