Compaq Infortrend Major Concerns, Redundant Cache Coherency Channels RCC, Channel Mode Assignment

8.2Major Concerns

Most of the configuration options in this chapter are directly related to controller redundancy. Joining two controllers into a dual-active pair can eliminate most possible points of failure. Configuring a controller pair requires careful planning and proper setup and the requirements can be summarized as follows:

!Redundant Cache Coherency Channels (RCC):

1. RCC	FC channels can be manually assigned as
	the dedicated communications loops, two
	are recommended for path redundancy and
	sufficient bandwidth.

2.Drive + RCC Communications traffic distributed over drive loops

!Connection between Controllers:

Cabling between controllers, hardware link through a common backplane, Fibre hub or switch (for SAN applications and for those models that do not have by- pass chips)

!Channel Mode Assignment

According to the topological plan, your I/O channels can be designated as:

•Host

•RCC paths

•Drive

•Drive + RCC

!Host Channel Connection Type:

This depends on the way your RAID system is connected to the host computer(s). The host connection type can be:

•FC-AL

•Fabric (point-to-point)

!Controller Unique ID:

This ID will be used to generate Fibre ports’ node names, and is necessary for addressing the controller during the controller failover/failback operation.

!Dual-Loop:

1.Drive-sidedual loop provides data path redundancy. Firmware is capable of executing a load-sharing algorithm to optimize dual-loop

8-2 Infortrend