diff between /dev/fcdX and /dev/tdX

[Kuntal Gupta]

Dear all,

Would any body pls brief the diff between:

1) /dev/fcdX and /dev/tdX

2)"Fibre Channel to Storage" and HBA

Regards...

Kuntal

[Torsten.]

Different models of FC cards will be related to different drivers and different drivers will create different device files (e.g. td0 and fcd0).


The second question is not clear ... ?

[Manix]

Different fiber channel models supports different drivers like tachyon & fc and hence they have different device files, depends on the cards model.

[Torsten.]

Manix, do you want to say anything different compared to my post?

;-)


However look at this ioscan output:

fc 0 0/3/1/0 td CLAIMED INTERFACE HP Tachyon XL2 Fibre Channel Mass Storage Adapter
/dev/td0


The driver column says "td".

And now:

fc 0 0/4/1/0 fcd CLAIMED INTERFACE HP AB379-60101 4Gb Dual Port PCI/PCI-X Fibre Channel Adapter (FC Port 1)
/dev/fcd0


the driver column says "fcd".

And now another different card:

fc 0 40/0/2/0/0/0/0/4/0/0/0 fclp CLAIMED INTERFACE HP AD222-60001 PCIe Fibre Channel 2-port 4Gb FC/2-port 1000B-T Combo Adapter
/dev/fclp0


Oh, a new driver: "fclp".


So you can see, each different driver creates different device files.

[Alzhy]

/dev/td devices are OLDER Tachyon (the chip) based FC HBAs (from the old Lucent spinoff?) They go only up to a max of 2Gbps. And are FC only cards.

/dev/fcd are QLogic based cards IIRC. They are faster and available in PCI-X and PCIe slot factors and can go 4Gbps+ and can be combo'ed with Gigabit ports on the same HBAs.

fcmsutil can be used to manage both cards.
fcdutil works exclusively on fcd HBAs.