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Using a CNA without a switch for FC only?

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distracted247

Occasional Visitor
I recently bought a server and I would like to connect it to a Fibre Channel Storage Array that I already own. I am on a very tight budget and I spent more than I intended to on the server hardware leaving me very little for the actual connection from Server to Storage.

I know that by buying a FC HBA I can make a direct connection from the server to the array but I can't find anything in my budget (pcie). Recently though, while I was searching for a HBA (daily! :rolleyes: ) I was offered a new IBM 42C1800 CNA card at a fraction of the asking price for a used single port HBA. :eek:
Thinking I had just made huge progress with my home SAN I accepted the deal and threw myself at google in search of FCoE information.

Things are never that simple though and I am sure you probably already know what I am about to say, but at the time I didn't.

A great deal of research later and all of a sudden my budget CNA purchase needs a $$$$$ switch to get it talking to my Fibre Channel storage; suddenly that bargain I scored is looking very, very, expensive.

Because FCoE hardware is relatively new and my knowledge on the subject (though growing) is limited, I am struggling to identify which switches support FCoE CNAs. Unfortunately even when I do manage to find these rare beasts, I take one look at their age and asking price and I know that they are incredibly unlikely to appear any-time soon in my price range.
On the other hand Fibre Channel technology is so much older and more widespread that supply outstrips demand and the hardware can be found at massively discounted prices. Everything that is, except the pcie HBAs which naturally is the only piece of this puzzle I am missing. Since these are still sought after(presumably) because they use the newer bus demand drives the asking price up so that even the oldest and most limited pcie HBA can command a premium that keeps them just out of my reach!

So now I'm a bit stuck, beyond trying to find a converged switch that's in my budget is there any way at all to make a direct connection from the CNA in my server to the storage Array?

I'm pretty sure I can't avoid the expensive hardware that takes the FCoE information and identifies, separates and forwards the FC signal to the array but I'm not going to rule it out before asking first.
If it simply can't be done point to point, can anyone recommend a switch or other hardware solution that I could use apart from a Cisco 5000/Brocade 8000 series (or OEM versions of them)?
Once I know what my options are, I should be well armed enough to decide which will be cheaper in the long-run; sell the CNA and go back to searching for a HBA solution, or stick with the CNA and head down the FCoE road. At this point based on the knowledge I've acquired since I picked up the CNA I'm fairly confident that it will be cheaper for me to sell the IBM card and start over with the HBA search, but I'm hoping someone here will tell me otherwise. :rolleyes:
 
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I recently bought a server and I would like to connect it to a Fibre Channel Storage Array that I already own. I am on a very tight budget and I spent more than I intended to on the server hardware leaving me very little for the actual connection from Server to Storage.

You probably understand this better than I do, a CNA adapter is a ethernet NIC and a FC HBA ( hence converged network adapter ). It is suppose to allow you to run ethernet and FC over the same cable.

I can't find anything that say it must go into a switch, so you can try point to point, see what happens, it may (though doubtful) work.

Find a Ether switch that has a SFP+ module for fiber, some if not most managed switches have slots for SFP modules. So you might be able to find a switch that supports a module, then find a module. Unlikely as that might be, it would probably be cheaper than a fiber switch that explicitedly support your CNA.

Or do as you are suggesting sell or trade the CNA for a PCIe fibre HBA.

As a bit of a warning to others, I recommend, as was done in the article, building a NAS first, make sure it works, than layer the additional parts on top of it.

The piece of kit, the QLogic CNA is cool, allows you to run 10Gbe throughout your network, with both fiber and network traffic along side each other.
 
Thanks Greg, I think I will end up selling it and searching for a HBA :(
 
Would it be possible to connect the CNA via SPF+ to a ethernet switch with FCIP support and then have that switch send and receive the FC portion of the FCoE signal to a FC entity (switch or array)?

Is that what you are suggesting Greg?

I must admit that I don't understand the function of the empty SFP ports on an Ethernet switch. Until now hadn't even thought they could be used for anything other than Ethernet traffic. Now though I'm thinking if the switch supports FCIP and I have the right SFP+ it might work...

As for point to point, I don't recall seeing it mentioned in the 'FC-BB-5 Standard' on fcoe.com/ but I am sure I read that it isn't currently supported. I think I saw a request to have it added to FC-BB-6 by IBM, but I could be way off; everything I know about this topic has been picked up in my spare time in the last few days, so unless I provide a link to the source consider it speculation :eek:
 
Would it be possible to connect the CNA via SPF+ to a ethernet switch with FCIP support and then have that switch send and receive the FC portion of the FCoE signal to a FC entity (switch or array)?

Is that what you are suggesting Greg?

I must admit that I don't understand the function of the empty SFP ports on an Ethernet switch. Until now hadn't even thought they could be used for anything other than Ethernet traffic. Now though I'm thinking if the switch supports FCIP and I have the right SFP+ it might work...

As for point to point, I don't recall seeing it mentioned in the 'FC-BB-5 Standard' on fcoe.com/ but I am sure I read that it isn't currently supported. I think I saw a request to have it added to FC-BB-6 by IBM, but I could be way off; everything I know about this topic has been picked up in my spare time in the last few days, so unless I provide a link to the source consider it speculation :eek:

That is exactly what I'm suggesting, you'd be ethernet on the other side of the switch. The switch would mediate the fiber to ether connection.

On the other point, the give it a shot. I'm suggesting ( this diagram ) that it might be possible to run FC point to point ( not FCOE, forego that ) via a CNA adapter: guess I'm saying plug the sucker in, run fiber between it and another FC target HBA and see what happens...ain't likely to explode, just not work. You might get lucky, there appears to be a full fiber HBA on the board.
 
The Fibre SAN I have is a Fibrecat sx80 and the ports on there are fixed on the raid controller which for better or worse binds me to FC.
Because of this I wont be able to create a point to point connection since it wont speak enhanced Ethernet. I should probably have used my noggin a bit more there since it was obvious if I thought about it.

As for the SFP+ ports on the switch idea, I will have to be careful to check that whatever switch I try supports 10 Gbit lossless enhanced Ethernet. But if I can find some hardware that looks promising at an obscenely low price and I can get my head around the setup in time, I'll have a crack at it.
It's serious food for thought at the moment even if it does turn into a dead end and frankly, half of the enjoyment I am getting out of this endeavour is the amount of research I am having to do to just to go from point to point! So if the CNA doesn't pan out and I end up selling it, it wont be wasted effort :D
 
The Fibre SAN I have is a Fibrecat sx80 and the ports on there are fixed on the raid controller which for better or worse binds me to FC.
Because of this I wont be able to create a point to point connection since it wont speak enhanced Ethernet. I should probably have used my noggin a bit more there since it was obvious if I thought about it.

I'm confused, and doing a web search didn't help, does the fibrecat provide a FC HBA port? Or is it something else? If it does provide a FC HBA port, take a machine ( the initiator ) put the CNA in it, then run fiber to the Fibrecat LC port ( the target ). And see if they will chat.

As for the SFP+ ports on the switch idea, I will have to be careful to check that whatever switch I try supports 10 Gbit lossless enhanced Ethernet. But if I can find some hardware that looks promising at an obscenely low price and I can get my head around the setup in time, I'll have a crack at it.
It's serious food for thought at the moment even if it does turn into a dead end and frankly, half of the enjoyment I am getting out of this endeavour is the amount of research I am having to do to just to go from point to point! So if the CNA doesn't pan out and I end up selling it, it wont be wasted effort :D

You should be able to run disparate FC adapters.

Best of luck.
 
You should be able to run disparate FC adapters.

Best of luck.

Do correct me if I'm wrong but I thought a CNA doesn't actually send a FC signal? To the best of my knowledge the only type of info it sends is an enhanced Ethernet Signal and all other information gets 'wrapped' in that signal using using Enhanced Ethernet headers etc (while preserving package without modification).
This is why I'm struggling to think of a cost effective way of using the CNA - if it wraps the FC signal at one end and then sends it out wrapped there must be something at the other end that understands the signal in such a way that it can identify the parts that need unwrapping, then unwrap them and pass them on to where they need to be. Since FCoE is made possible by lossless Enhanced Ethernet which isn't the same as standard Ethernet anything that isn't compatible wont know what to do with it. And because the FC signal isn't visible (in transport its an enhanced Ethernet signal) a standard FC adaptor will only see the Ethernet portion and react accordingly.

It would be a bit like a translation but because the transported signal isn't modified in any way (i'm aware of) i'm steering clear of this and saying wrapping/transporting.

So what you get with your CNA is a single type of signal for all communication in the Data Centre which can carry other types of signal by wrapping them in its own signal then unwrapping them at their destination. That way the standards of FC etc are preserved while the network is converged into one cable that has a standard everyone can agree on (maybe :rolleyes:)


I may be way off with my understanding but if all the above holds true and a target were to receive FC communication from a CNA the target would still only see an enhanced Ethernet package (the wrapping) unless it could unwrap that package - obviously this is fine if you are sending Ethernet to Ethernet but for encapsulated information if you can't read the lable to see whats in there and unwrap it you can't work with the contents. Since older FC hardware has no way of dealing with FCoE all it will see is the wrapping and with no way to unwrap it or understand the Ethernet signal, it will respond as though it hadn't received any FC info, even though the info is there just waiting to be unwrapped.


I hope that makes sense, it does to me but I know in explaining it I made a lot of errors with basic terminology but the message should be okay. If I go off to try and find the right terms now I'll never get this reply written! :p Anyway please do correct me where I'm wrong, like I keep saying, it's all very new!

Hopefully by explaining what I understand about FCoE you can see why I'm struggling to come up with a way to make the CNA talk to the Fibrecat?
Right it's 1am, time for bed! I'll edit when I'm a little less foggy :rolleyes:
 
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Do correct me if I'm wrong but I thought a CNA doesn't actually send a FC signal? To the best of my knowledge the only type of info it sends is an enhanced Ethernet Signal and all other information gets 'wrapped' in that signal using using Enhanced Ethernet headers etc (while preserving package without modification).
This is why I'm struggling to think of a cost effective way of using the CNA - if it wraps the FC signal at one end and then sends it out wrapped there must be something at the other end that understands the signal in such a way that it can identify the parts that need unwrapping, then unwrap them and pass them on to where they need to be. Since FCoE is made possible by lossless Enhanced Ethernet which isn't the same as standard Ethernet anything that isn't compatible wont know what to do with it. And because the FC signal isn't visible (in transport its an enhanced Ethernet signal) a standard FC adaptor will only see the Ethernet portion and react accordingly.

It would be a bit like a translation but because the transported signal isn't modified in any way (i'm aware of) i'm steering clear of this and saying wrapping/transporting.

So what you get with your CNA is a single type of signal for all communication in the Data Centre which can carry other types of signal by wrapping them in its own signal then unwrapping them at their destination. That way the standards of FC etc are preserved while the network is converged into one cable that has a standard everyone can agree on (maybe :rolleyes:)


I may be way off with my understanding but if all the above holds true and a target were to receive FC communication from a CNA the target would still only see an enhanced Ethernet package (the wrapping) unless it could unwrap that package - obviously this is fine if you are sending Ethernet to Ethernet but for encapsulated information if you can't read the lable to see whats in there and unwrap it you can't work with the contents. Since older FC hardware has no way of dealing with FCoE all it will see is the wrapping and with no way to unwrap it or understand the Ethernet signal, it will respond as though it hadn't received any FC info, even though the info is there just waiting to be unwrapped.


I hope that makes sense, it does to me but I know in explaining it I made a lot of errors with basic terminology but the message should be okay. If I go off to try and find the right terms now I'll never get this reply written! :p Anyway please do correct me where I'm wrong, like I keep saying, it's all very new!

Hopefully by explaining what I understand about FCoE you can see why I'm struggling to come up with a way to make the CNA talk to the Fibrecat?
Right it's 1am, time for bed! I'll edit when I'm a little less foggy :rolleyes:

The blind leading the blind here.

I suspect you are correct, the connection is ether over fiber. The question you are asking, is the one I'm asking. What I'm saying is that the CNA has a LC port, the fibrecat has an LC port, see what happens when you connect them. Maybe they will auto-negotiate an FC connection. I doubt it, but like I said it won't explode, what is the harm in trying?

Your next choice is an SPF connect to a ether switch, and then ether to clients, with the switch mediating the conversion.

Choice after that is trade or sell the CNA.

Final choice, build a small altar, perform a thermite sacrifice of the CNA in a burst of flame to the gods of computing, hoping they will shine down on you with a solution.

Have you figured out what OS you are going to be running on the Fibrecat?
 
Final choice, build a small altar, perform a thermite sacrifice of the CNA in a burst of flame to the gods of computing, hoping they will shine down on you with a solution.

Should I use marble do you think? ;)
 
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Have you figured out what OS you are going to be running on the Fibrecat?

I'm going to start with Windows server 2008 or 2008r2 then once I know everything is working and set up correctly I might move on to another even less familiar OS.
 

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