Wrong WWN being reported

[Jason Fischer]

We have a couple of Proliant BL20p's connected to an EVA SAN using Qlogic fibre channel cards. We've set up one of the servers already on the SAN without any problems and it's running fine.

We're now setting up the second server, but having problems with it's WWN. I've got the HBA configured on it just like the working server, but the WWN that the SAN switch see's isn't correct. The actual WWN is 5005 08B2 00C6 4F22, but the SAN switch sees it as 5005 08B2 00C6 4F20.

Any ideas on why this is? Let me know if you need more details.

Thanks.

[Uwe Zessin]

Jason,
if the switch says: 5005 08B2 00C6 4F20, I think you can trust it.

May I ask where did you get the value "5005 08B2 00C6 4F22" from? Is this, by change, a misplaced label or does the blade have two FC port and ...4F22 is the WWPN of the other port?

Have you tried to go into the adapter BIOS? It should have a feature do display the WWN.

[Jason Fischer]

Uwe,

I got the value from the sticker on the HBA and from the BIOS. The blade does have two FC ports, one is 4F22 and the other is 4F23.

Do you think we'll be fine to just go ahead in configure the SAN?

Thanks for your reply

Jason

[Uwe Zessin]

No, I would definitely not just skip this!!

Next thing I suggest to do is check the other blades - I suspect this is a cabling 'problem' and the WWN belongs to another blade.

[Jason Fischer]

Uwe,

We only have two blades, and each blade has a two port HBA in it. The first blade we set up is reporting the correct WWN to each SAN switch, and is active on the SAN.

We have the cabling on this problem blade identical to that of the first, so I don't think that that's the cause (I could be wrong!).

Thanks.

Jason

[Steven Clementi]

Jason:

All Qlogic blade HBA's usually have the same last number for their ports. What I mean is... the first port will ALWAYS end with "2" and the second port with "3".

Where are you seeing "4F20? in the name server? WHat about if you telnet to the switch and do a "switchshow"? Usually a "0" indicated a WWN or the Node Address. Make sure you are readign the right column in the Name Server. Therei s one for Node Device and one for Port Device. The port device column is the numbers you usually see stamped on the card and through the bios utility.


Steven

[Jason Fischer]

Steven,

We typed 'switchshow' at the prompt on the SAN switch, and it did show the current WWW number. We went back into the web-based switch managment console and found out that if you expand the 4F20 WWN, it shows the correct WWN 4F22. (See attached). The other Qlogic device with WWN 7382 shows 7382 as well when expanded. Perhaps that one is wrong and the way 4F20 is set-up is right!

What's the difference between Node Device and Port Device? Is Node the actual HBA card, and Port one of it's two ports?

Thanks for your help.

Jason

[Uwe Zessin · Accepted solution]

Yep, that's it. The WWPN (World Wide Port Name) is unique for any physical port. The intention of the WWNN (World Wide Node Name) is to be identical for all Fibre Channel ports within the same device, but that is not always the case. E.g. if you have a server that uses two different Fibre Channel Adapters in two different PCI slots. Each adapter has its own WWPN and WWNN. Sometimes it is possible to tell the device drive to register on WWNN for all FC ports.

So the label is correct, but the switch is correct as well ;-) except that the label shows the WWPN, while you have seen the WWNN.

I usually prefer to login via character cell interface and do the "switchShow" command, which lists what WWPN is connected to what switch port.

[Steven Clementi]

"Perhaps that one is wrong and the way 4F20 is set-up is right!"

I can not say I honestly paied any attention to what the node id's were on all the blades I have installed the past 3 years, but I would think that both ID's that you have are correct. The Node ID doesn't necessarily have to follow suit where all the fibre mezzenine cards have a "0" as the last character of the node id so you could indeed have the right 2 ID's showing.

If you are in the least bit worried about it perhaps it is worth a call to HP, but I think it's fine as long as your storage array can see the WWPN so you can configure it.


Steven