Optical link failures

You might need to replace the small form-factor pluggable (SFP) transceiver when a failure occurs on a single Fibre Channel or 10G Ethernet link (applicable to Fibre Channel over Ethernet personality enabled 10G Ethernet link).

Before you begin

The following items can indicate that a single Fibre Channel or 10G Ethernet link failed:
  • The Fibre Channel port status on the front panel of the node
  • The Fibre Channel status light-emitting diodes (LEDs) at the rear of the node
  • An error that indicates that a single port failed (703, 723).

About this task

Use only IBM® supported 10 Gb SFP transceivers with the SAN Volume Controller 2145-DH8. Using any other SFP transceivers can lead to unexpected system behavior. Copper DAC is not supported by these 10 Gb ports. The SFP transceiver replacement in a 10 Gbps Ethernet adapter port is governed by the following rules:
  • An existing 10 Gb SFP transceiver that is replaced with a new 10 Gb SFP transceiver: The 10 Gbps Ethernet adapter port detects a new SFP transceiver and becomes operational immediately.
  • If the 10 Gbps Ethernet adapter port detects a new SFP transceiver and becomes operational immediately, the port has an incorrect SFP transceiver since the last reboot. The SFP transceiver is then replaced with the correct 10 Gb SFP transceiver. This situation can occur with an incompatible SFP transceiver (8 Gb SFP or 4 Gb SFP) that is inserted in the 10 Gbps Ethernet adapter port.
    • The node requires a reboot for detecting the new SFP transceiver. The new SFP transceiver will be operational only after reboot (no DMP is produced).
  • The 10 Gbps Ethernet adapter port contains no SFP transceiver since the last reboot and the correct 10 Gb SFP transceiver is installed:
    • System reboot is required for detecting the new SFP transceiver.

Procedure

Attempt each of these actions, in the following order, until the failure is fixed.

  1. Ensure that the Fibre Channel or 10G Ethernet cable is securely connected at each end.
  2. Replace the Fibre Channel or 10G Ethernet cable.
  3. Replace the SFP transceiver for the failing port on the node.
    Note: The system is supported by both longwave SFP transceivers and shortwave SFP transceivers. You must replace an SFP transceiver with the same type of SFP transceiver. If the SFP transceiver to replace is a longwave SFP transceiver, for example, you must provide a suitable replacement. Removing the wrong SFP transceiver might result in loss of data access.
  4. Replace the Fibre Channel adapter or Fibre Channel over Ethernet adapter on the node.