Accusys ExaRAID GUI - Manual (Page 191)

Advanced Functions
5-18
Configuration Tasks
5.3 Redundant Controller
5.3.1 Overview
Redundant controller is a high-availability solution for ensuring system
availability against controller failure and for improving the performance
by doubling the I/O processing power. A redundant-controller system
incorporates two active-active controllers that can service I/O
concurrently and take over each other if any controller fails. This section
introduces basic concept of redundant-controller operations.
• Dual controller configuration and status synchronization
The two controllers synchronize with each other by the dedicated high-
speed Redundant-controller Communication Channels (RCC) on the
system backplane. The synchronization allows a controller to know the
configurations and status of the peer controller, such that it can take over
the jobs of a failed peer controller. It also allows you to access any one
controller to monitor the status of the system or to do configurations for
both controllers.
Tasks Instructions
Create Virtual volumes and
specify the preferred
controller RAID Management > Disk Groups >
Create DG0 and DG1
RAID Management > Logical Disks >
Create DG0LD0 > Specify the
preferred controller as ctla
RAID Management > Logical Disks >
Create DG0LD1 > Specify the
preferred controller as ctla
RAID Management > Logical Disks >
Create DG1LD0 > Specify the
preferred controller as ctlb
RAID Management > Logical Disks >
Create DG1LD1 > Specify the
preferred controller as ctlb
Select Controller Failover
mode Multiple-ID
Select Storage Provisioning
method RAID Management > Storage
Provisioning > Simple
Specify the LUN ID and map
LUNs to fiber ports fcpa1 -> DG0LD1
fcpa2 -> DG0LD0
fcpb1 -> DG1LD1
fcpb2 -> DG1LD0