Problem: SAS cabling not valid

If a SAS connection is not valid, use this information to verify the accuracy of the system cabling.

Procedure

Verify that the SAS cabling is installed correctly by checking that all SAS connections meet the following requirements.

  1. If a connection between the control enclosure and any host in the system is not valid, check that the SAS cabling between the control enclosures and the hosts conforms to the following SAS connectivity rules.
    • Only ports 1 and 2 of node canisters connect to hosts.
    • Ports 1 and 2 of node canisters cannot connect to expansion enclosures or other storage systems.
    • The cables that are connected to port 1 on each node canister in a control enclosure must attach to a redundant port pair on a host.
    • The cables that are connected to port 2 on each node canister in a control enclosure must attach to a redundant port pair on a host.
    • A connected port on the node canister must connect to a single port on a host. Cables that split the connector out into separate physical connections are not supported.
  2. If a connection between the control enclosure and any expansion enclosures in the system is not valid, check that the SAS cabling conforms to the SAS connectivity rules in the "SAS cabling guidelines" topic.
  3. If a connection between the control enclosure and any expansion enclosures in the system is still not valid, check that the SAS cabling conforms to the SAS connectivity rules.
    • A control enclosure is connected to its first expansion enclosure by cabling from port 4 of each node canister in the control enclosure to port 1 of the corresponding canister in the expansion enclosure. Hence, two cables connect this expansion enclosure to its control enclosure.
    • Each additional expansion enclosure is connected to the chain end enclosure by cabling from port 2 of each canister in the chain end enclosure to port 1 of the corresponding canister in the additional enclosure. Hence, there are two cables connecting any two expansion enclosures together.