You receive the error shown below on a FAS2750 HA pair.

The controller of controller A should be replaced. The error reports an unknown device on adapter 0a from NetappA, with a SCSI check condition indicating a hardware error. In the cabling context of a FAS2750 HA pair, if the system is cabled according to the exhibit and the error remains isolated to controller A's path, the fault follows the controller-side hardware rather than the partner controller or only an external cable. Re-cabling per the guide would be appropriate if the exhibit showed incorrect cabling, and replacing a cable would be appropriate if the fault evidence isolated to the cable. Replacing controller B does not align with the reporting node and adapter. A support engineer should first map the error to node, adapter, shelf path, and cabling; then isolate whether the failing element is the controller path, cable, or external shelf component. Here, the reported hardware error points to controller A. References/topics: FAS2750 SAS path troubleshooting, SCSI check condition errors, controller path isolation, HA cabling validation, and hardware replacement workflow.