Fibre Channel Node Name question?

[robbo79871]

Hi, when you issue the show FLOGI database command and it gives you the WWPN's and WWNN's, as far as i was aware the Node Name corresponded to a HBA card and the WWPN corresponded to each individual port on the HBA. In this example:

https://overlaid.net/2014/08/16/fibre-channel-fc-basics-for-ccie-dc/

On the zoning section on the article he connects the servers WWPN to the storage array disk 1, could someone explain to me how he'd have it setup there? Would the MDS switch connect to the storage array server with one connection into a HBA on the storage array and if that is the case why are there multiple node names for the one HBA and multiple WWPN's. This cant be the case since he mentions 8 disks and there are 8 entries with different WWPN's and WWNN's for each. 

So does each disk carry with it a unique WWPN and WWNN? i guess the part that is confusing me is how is one cable from the MDS to the storage server getting back 8 different WWPN's and WWNN's?

Thanks for the help, new to fibre channels

[joelsprag · Accepted solution]

Typically you would see one WWNN, as you would be using a storage array, such as a Netapp or EMC SAN.  In the screenshot, he is using a JBOD (Just a Bunch Of Disks), which is likely a standalone disk shelf from one of these SANs.  These disk shelves act as an FCAL (Fiber channel Arbitrated Loop), where each disk is individually accessible, each with their own WWNN/WWPN. 

When these disk shelves are attached to a controller, such as a Netapp FAS3170, the controller has multiple FC ports.  One set of ports would connect to the disk shelf (accessing each of those disks individually over the FCAL), while another set of ports would be presented to the MDS and accessible from the server, via the storage controller's WWPN/WWNN. 

So yes, for normal use you would see a single WWNN/WWPN on that port (or a single physical pair, and possibly additional logical pairs, if using SVMs/LIFs on Netapp, or similar constructs on other vendor hardware)