FC in NAS

[saranraj456]

Hi,

Why cant we use a Fibre channel connectivity to NAS environment....?

What kind of restrictions are there>

Thanks.

Saran

[radek_kubka]

Hi Saran,

Your question is really confusing , but somewhat intriguing as well.

The best answer I can think of is, that any protocol used by NAS must be "understood" by the client OS - this is where CIFS & NFS protocols are coming from.

You can use optical cabling for running CIFS & NFS on top of TCP/IP, if it makes any difference.

And I also think that Enhanced Ethernet / Data Centre Bridging idea is basically about making Ethernet as "good" in certain areas (e.g. losslessness)  as Fibre Channel.

Regards,

Radek

[scottgelb]

agreed...mixing of the terms.  But NetApp supports natively both SAN and NAS protocols.. intriguing is some of the cool stuff that is mixed with all running concurrently.  For example, being able to loopback to lun device over nfs or the ability to ndmp backup a lun.  But typically to best practice on a per volume basis use NAS (cifs, nfs, etc.) or SAN (fcp, iscsi, fcoe), but not both (although it can be for both but isn't recommended).

[saranraj456]

HI Radek,

My concern is NAS was slow when compared to SAN , inorder to improvise that, if we use FC connectivity on top with TCP/ IP (as you mentioned above) will that make any difference ?

THanks,

Saran

[arunchak]

Hi,

In that case you can try FCoE. i.e. FC over Ethernet. NetApp supports that.

Thanks,

  Arun

[scottgelb]

Good point..and as of 8.x many customers with only 10GbE and no FCoE are still using the FCoE HBAs for ethernet only and they have the flexibility for FCoE when/if they upgrade their switch fabric.

[MATTBAKER]

NAS isn't really slow compared to SAN. If you're using 10G links, there's not much you can't do. Oracle is certified for use on NFS, as is VMware. Do you have a specific app that has issues with NAS connectivity?    

[akw_white]

Barring some kind of experimental feature of hack I am not aware of, I reckon the answer would have to be "no". In theory there is such a thing as IP over FC but I've never heard of NetApp supporting it. The FC ports in the NetApp array are storage adapters not network interfaces.

If you're concerned about bandwidth restrictions on Ethernet you should consider 10 GBE. Interface groups/VIFs with LACP and nultuple IP aliases may also help to increase available bandwidth, depending on your requirements.

[saranraj456]

No, really my need was to know ,any possibility to use NAS protocol in FC medium ?

[arunchak]

Do you mean IP protocol in FC medium? NAS communication happens over TCP/IP.

Something similar to your requirement is FCoE http://en.wikipedia.org/wiki/Fibre_Channel_over_Ethernet

Thanks,

   Arun

[MATTBAKER]

If by FC medium, you just mean fiber, then yes. You can run NAS over 10G fiber links. Fiber Channel is a completely separate protocol and can't be used for NAS, but both TCP/IP and FC protocols can be used over fiber optic links.

[radek_kubka]

I love academic discussions!

So to make things complete, it is worth to mention that Cisco uses something called IPFC in their MDS & Nexus range:

http://www.cisco.com/en/US/products/ps5989/products_configuration_guide_chapter09186a00806630a5.html#wp1228088

"IPFC provides IP forwarding or in-band switch management over a Fibre Channel interface (rather than out-of-band using the Gigabit Ethernet mgmt 0 interface). [...] IP frames are encapsulated into Fibre Channel frames so NMS information can cross the Fibre Channel network without using an overlay Ethernet network."

It is a very corner case, but shows that FC network (not just an optical cable) can actually pass IP frames.

Regards,

Radek

[aborzenkov]

It is not in any way Cisco specific. Emulex HBA could use it since the very first day I met them (I think at least Linux dropped support for IP now). Brocade switches always supported in-band management as well (and of course could forward IPoFC from HBA). Actually, even NetApp used it for SnapMirror over FC

[radek_kubka]

True - I completely forgot about SnapMirror over FC, which in fact is as close as it gets to NAS over FC

(with the difference that in this case NetApp owns both ends)

[scottgelb]

I think that QLogic fcip hba is going EOA though. We have some customers using them. Slick how we could setup active passive source connections using the hba and a nic for snapmirror.

[peter_lehmann]

IMO one of the worst worded questions since the opening of the communities...