The issue with the Qlogic HBA stems from the fact that the older Qlogic HBAs will not PLOGI into storage devices that have the same area in the FCID.
FCID is like DDAANN
DD is the domain ID where the device is FLOGI'd into
AA is the area assigned by the switch
NN is the port number.
So if Stroage array logs into MDS and is assigned FCID 330000, and then Qlogic HBA logs in and is assigned FCID 330001, the HBA will not PLOGI into the storge array because both have 00 in the area portion of the FCID. To bypass this, MDS has a list of OUI that have this issue, and if it sees those OUI at FLOGI time (which is part of the PWWN of the attaching device), the MDS will issue an unused area. The result would be that the storage array was given FCID 330000, and the next device that logged in had an OUI in the list, the MDS would assign it 330100. Now with the HBA having area 01, and the storage unit haveing 00, the issue is not seen.
The company list maintained in the code...and what this is a list of OUI (Organizationally Unique Identifier) that are assigned to a specific company. The company that then manufactures fibre channel devices, would use this OUI in the PWWN of any device they manufacture. The MDS uses this OUI to tell if the device that is logging in is one that needs a unique area number in the FCID. One company can have many OUI assigned to them.
The command 'show fcid-allocation area' will show the current list of OUI that the MDS would assign unique area for. If you happen to discover a new OUI that requires a unique area, and it is not in the list, you can add it to the config to make the MDS assign it a unique area. Likewise, you can remove OUIs from the default list if needed. If you need to check the OUI in a PWWN, you can issue this command on the MDS.
'show fcid-allocation company-id-from-wwn xx:xx:xx:xx:xx:xx:xx' and the MDS will show you the 3 byte OUI. For reference, if the PWWN starts with 2 the OUI is differnt that if it starts with 5. I have underlined the OUI for 2 PWWN below.
50:00:40:21:03:f4:62:b6
21:01:00:1b:32:31:8c:79
What the goal is to have any Qlogic HBA that need to work with Storage array on MDS where the BAG is attached, end up with different area numbers in their assigned FCIDs. In order to do this, I do not think you would need to suspend the VSAN. I would recommend making the attachments, and then determine what FCIDs need to be zoned together in your environment, and then make a decision. Remember there is also a limitation on the BAG that the last byte of the FCID not be the same on any 2 devices. I would recommend option D in that document you posted the link to. It would be the most none disruptive. The FCIDs you assign would have to be inline with the current domain ID of the VSAN you have the BAG attached to.
IE: if BAG is attached to MDS VSAN 100, and the domain for VSAN 100 is 0x33
- use 'show flogi data vsan 100' to see currently assigned FCIDs for VSAN 100
- configure static entries for any new pwwn that will reside behind the BAG confirming to:
- using FCIDs that are not currently in use
- assign unique area
- assign unique port number
You can always attach the BAG and the servers and see what FCIDs they end up with. If the connectiviy issue surfaces, it will only be once the devices are zoned together, and would not imact any other devices on the SAN. Once the FCIDs are determined, you will then know if any issues 'might' arise.
HTH,
Mike
