Server Administrator Storage Management 8.3 User’s Guide

Setting The Redundant Path Configuration

Does my Controller Support This Feature? See Supported Features.

Redundant path is supported only on external PERC cards that use firmware version 6.1 and later. A redundant path internal to the system is not supported. MD1xxx enclosures are supported.

For redundant paths, the enclosure must be in the Unified mode however specific port connections are not required. A connection from either controller ports to either EMM In ports creates the redundant path as long as two cables are used. But, Redundant Path continues to appear in the field even as the redundant path is removed. The redundant path ceases to appear only when it is cleared in the storage management.

In a daisy-chain scenario, more than one enclosure can be connected to a controller in a redundant path mode. You can connect up to three MD1000 and MD1120 to a PERC 6/E controller in a daisy-chain enclosure. You can connect up to four MD1200 and MD1220 to a PERC H800 and PERC H810 controller in a daisy-chain enclosure. You can connect up to four MD1400 and MD1420 to a PERC H830 controller and SAS 12 Gbps adapter in a daisy-chain enclosure. For an example of a daisy-chain configuration (for PERC 6/E controller), see the following image:

If the communication channel between the connector and the first enclosure is lost, the redundant path configuration is lost. In this case, the health of the logical connector is displayed as critical. Navigate to the Information/Configuration page of the logical connector to view details of the Path Health. For a brief outline of this scenario, see the following table:

Table 1. Path between Controller and Enclosure 1

Health of Logical Connector	Path between Controller and Enclosure 1
	Connector 0 (C0)	Connector 1 (C1)
	Available	Available
	Available	Disconnected
	Disconnected	Available

However, if the communication channel between any two enclosures is lost, the redundant path configuration is degraded and the health of the logical connector is displayed as degraded. For a brief outline of this scenario, see the following table.

Table 2. Path between Enclosure n and Enclosure n +1

Health of Logical Connector	Path between Enclosure n and Enclosure n +1
	Connector 0 (C0)	Connector 1 (C1)
	Available	Available
	Available	Disconnected
	Disconnected	Available

In the above scenario, the enclosure status is displayed in warning mode. Clicking Information/Configuration in the Enclosures page displays all enclosure components (EMMs, Fans, Physical Disks, Power Supplies, and Temperature) in normal condition. To view the Path Failure message to indicate that the enclosure has lost a communication path to the controller, indicating that the enclosure is no longer in redundant path mode.