When adding an expansion enclosure to a Dell PowerStore, the SAS cabling follows a redundant, cross-connected topology. For each of the two SAS chains, the connection extends from the B port of the last existing enclosure to the A port of the new enclosure. This B-to-A daisy-chain continues for all subsequent enclosures. The chain is completed by cabling the B port of the final enclosure to a SAS port on the alternate node (the node that did not originate the chain). This design ensures high availability and that there is no single point of failure at the node or path level, as each node has access to all enclosures through a separate SAS chain.

A. This is incorrect because the SAS chain must return to the alternate node to provide redundancy, not the originating node.

B. This is incorrect. The daisy-chain connection between enclosures is from port B to port A, not A to B. Additionally, the return path originates from port B of the last enclosure, not port A.

D. This is incorrect because the SAS chain must return to the alternate node for high availability, not the originating node.

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1. Dell PowerStore 500T, 1200T, 3200T, 5200T, and 9200T Hardware Information Guide:

Section: "Cable the expansion enclosure" (Page 45 in the March 2024 revision). The diagrams and instructions explicitly show the cabling path: "To add another expansion enclosure to the chain, connect a SAS cable from port B on the embedded module in the preceding expansion enclosure to port A on the embedded module in the next expansion enclosure." It also states, "To connect the last expansion enclosure in the chain back to the base enclosure, connect a SAS cable from port B on the top embedded module in the last expansion enclosure to SAS port 1 on node B." This confirms the B-to-A daisy chain and the return from port B to the alternate node.

2. Dell PowerStore: Introduction to the Platform White Paper:

Section: "Backend Connectivity" (Page 13 in the April 2024 revision). The figure "Backend SAS Connectivity" illustrates the two redundant SAS backend chains. It clearly shows each chain starting from one node, daisy-chaining through the expansion enclosures, and terminating on the peer node, confirming the cross-cabling principle for high availability.