Users Guide

Table Of Contents
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 four MD1400 and MD1420 to a PERC H840 controller and SAS 12 Gbps adapter in a daisy-chain connection.
For information about using the single and multiple multipath connections on 4-port controllers, see Set up single and multiple
multipath connections. 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 14. 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 15. 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 Degraded
Disconnected Available
66 Controllers