San Problem Determination; Fibre Channel Link Failures - IBM Storwize V7000 Troubleshooting And Maintenance Manual

SAN problem determination

The procedures that are provided here help you solve problems on the Storwize V7000 system and its
connection to the storage area network (SAN).
SAN failures might cause Storwize V7000 drives to be inaccessible to host systems. Failures can be caused
by SAN configuration changes or by hardware failures in SAN components.
The following list identifies some of the hardware that might cause failures:
v Power, fan, or cooling switch
v Application-specific integrated circuits
v Installed small form-factor pluggable (SFP) transceiver
v Fiber-optic cables
Perform the following steps if you were sent here from the error codes:
1. If the customer has changed the SAN configuration by changing the Fibre Channel cable connections
or switch zoning, ask the customer to verify that the changes were correct and, if necessary, reverse
those changes.
2. Verify that the power is turned on to all switches and redundant array of independent disk (RAID)
controllers that the Storwize V7000 system uses, and that they are not reporting any hardware
failures. If problems are found, resolve those problems before proceeding further.
3. Verify that the Fibre Channel cables that connect the systems to the switches are securely connected.
4. If the customer is running a SAN management tool that you are familiar with and that you have
access to, you can use that tool to view the SAN topology and isolate the failing component.

Fibre Channel link failures

When a failure occurs on a single Fibre Channel link, the small form-factor pluggable (SFP) transceiver
might need to be replaced.
The following items can indicate that a single Fibre Channel link has failed:
v The customer's SAN monitoring tools
v The Fibre Channel status LEDs at the rear of the Storwize V7000 node
v An error that indicates that a single port has failed
Attempt each of the following actions, in the following order, until the failure is fixed:
1. Ensure that the Fibre Channel cable is securely connected at each end.
2. Replace the Fibre Channel cable.
3. Replace the SFP transceiver for the failing port on the Storwize V7000 node.
Note: Storwize V7000 nodes are supported with 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 could result in loss of data access.
4. Perform the Fibre Channel switch service procedures for a failing Fibre Channel link. This might
involve replacing the SFP transceiver at the switch.
5. Replace the Fibre Channel adapter on the Storwize V7000 node.
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Storwize V7000 Version 6.1.0: Troubleshooting, Recovery, and Maintenance Guide