Diagnosing FC path down?

[Jeremy C]

Say you have a FC path go down between a server and a SAN switch. Is there anything to indicate if it's the cable, SFP, or HBA? I'm just wondering if there is a better way than physically replacing parts until you find what fixes it.

Specifics to my situation: Windows servers, QLogic or Emulex HBAs. HP (rebranded Brocade) SAN switches.

[Torsten.]

I'm not aware of any. The hardware only knows there is no link, but doesn't know if this is the cable or the emitter.

[ks6542]

Well if you see the port properties you will see the sfp info.. it will display the current statistics..
if its faulty it wont show .. this is one of the way to identify the problem between cable & sfps.

[Uwe Zessin · Accepted solution]

A steady amber light on a brocade switch port indicates that it does receive light, but it cannot establish a link. It could be a problem with the port sender, the cable or the receiver.

There is also a customer advisory with some useful information:
c01392475 - HP StorageWorks B-Series Switches - Identifying if SFP or the Cable is the Cause for Loss of Link
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c01392475

As usual, the formatting is bad. Here are the last lines:

enc_out -> Encoding error outside of frames
crc err -> Frames with CRC errors
Lr_in -> Link reset In (primitive sequence), does not apply to FL_Port
Lr_out -> Link reset Out (primitive sequence), does not apply to FL_Port
Ols_in -> Offline reset in (primitive sequence), does not apply to FL_Port
Ols_out -> offline reset out (primitive sequence), does not apply to FL_Port