Understanding CRC Errors: CRC (Cyclic Redundancy Check) errors occur when the data received at a port does not match the checksum sent by the initiator or switch. In a Pure Storage environment, these are tracked per port and can be viewed via the CLI (purehw list) or the GUI.

Configuration vs. Hardware: While a failing SFP or a damaged fiber cable can cause CRC errors, they are a primary indicator of configuration mismatches in the SAN fabric. Common culprits include:

Port Speed Mismatches: Manually setting a port to 16Gbps when the switch is set to " Auto " or 8Gbps.

Duplex Mismatches: Though rare in modern Fibre Channel, it is a classic Ethernet/iSCSI configuration error.

MTU Mismatches: In iSCSI or NVMe-oF environments, if the FlashArray is configured for Jumbo Frames (MTU 9000) but the switch or host is at MTU 1500, packet fragmentation or CRC-like errors/drops will occur.

Why Option A is incorrect: A blinking status LED on a controller is often part of normal operation (indicating heartbeat or activity). A solid amber LED would be an indicator of a hardware failure, not necessarily a misconfiguration.

Why Option C is incorrect: While latency spikes can be caused by misconfiguration (like incorrect MPIO settings), they are more commonly symptoms of workload changes , " noisy neighbors, " or reaching the physical performance limits of the array. CRC errors are a much more specific diagnostic " smoking gun " for port and fabric configuration issues.

Best Practice: When CRC errors are detected, Pure Storage recommends first checking the physical layer (reseating SFPs/cables) and then verifying that the port speed and protocol settings on the FlashArray match the upstream switch configuration exactly.