Infortrend RAID Controller Manual

9.3 Configurable Options Related to Cabling
Topologies
HBAs:
Fibre channel is widely applied to storage configurations with
topologies that aim to avoid loss of data by component failure. To
avoid single point of failure, the connections between source and
target should be configured in redundant pairs. The recommended
host side connection should consist of two host adapters. Each host
adapter is used to configure a loop between host computer and
storage.
In active-to-active redundant controller mode, the primary loop serves
the I/O traffic directed to the primary controller, and its pair loop
serves that to the secondary controller. The host-side management
software directs I/O traffic to its pair loop should one of the
redundant loops fail.
Considerations for Redundant Controller
Configuration:
Active to Active Redundant Controller:
Using two HBAs in each server ensures continued operation when a
data path fails.
With redundant paths, the connection to each host bus adapter
should be considered a data path connecting host to the primary or
the secondary controller. Multiple IDs can also be assigned on a
single host loop, letting I/Os to be directed to both controllers via the
same loop. To avoid single point of failure, one loop should be
configured to serve the primary controller, and the other the
secondary. Each of the target IDs on host channels should be
assigned as either a primary ID or a secondary ID. Should one
controller fail, the existing controller can inherit ID settings from its
counterpart and activate the once standby channel (chip) to continue
host I/Os.
Fibre Operation 9-5