Configuring listener (especially WWPN) in SPDK NVMe-oF FC transport
by 松本周平 / MATSUMOTO,SHUUHEI
Hi Anil,
Thank you for improving the patch continuously. I have seen great improvement.
I have an item to discuss with you, and I send it to the mailing list first.
Please correct me if I'm wrong or let's discusss on Trello by creating the board for FC if this question is reasonable.
NVMe-oF FC transport utilizes two types of WWN.
WWPN is a World Wide Port Name, WWPN is an unique ID for each FC port, and each port on a FC HBA has a unique WWPN.
WWNN is a World Wide Node Name and WWNN is assigned to a FC HBA.
If I understand correctly,
The FC low level driver (LLD) reads persistent WWPN and WWNN and informs them to SPDK NVMe-oF transport,
then SPDK NVMe-oF transport configures listeners according to them.
Besides, nvmf_fc_listen is implemented as NOP.
So WWPN and WWNN is read-only for SPDK NVMe-oF transport.
But it is very desirable if we can change WWNN and WWPN as our own needs.
.INI config file has been deprecated and could you consider to add FC code to the nvmf_subsystem_add_listener RPC?
Implementation options may be for example
- to pass the pair WWNN and WWPN to LLD, and LLD change the WWPN of the HBA which matches WWNN.
or
- FC port has its own PCI address.
- user passes the trio, PCI address, WWNN, WWPN.
- if the PCI address is the lowest of the FC HBA, WWNN can be changed.
If FC HBA doesn't allow changing WWNN or WWPN, we can output error message.
Thanks,
Shuhei