Rackable Systems OmniStor 4900F Series, User Manual

Page: 46 / 196

Chapter 2 - Topologies and Operating Modes
Multi-Port Mirrored Single Host-Dual Connection
32
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.
Duplex Mode Logical View - Multi-Port Mirrored Single Host-Dual Connection
In this topology the Host I/O card switch 1, 2, and 6 are set to the “Up” position.
Switch 1 sets the bus speed mode on the Host I/O card to 2 GB/sec.
Switch 2 configures the enclosure for the Wahoo2 RAID Controller.
Switch 6 enables automatic internal hub failover during a controller failure.