Which slot to insert the 4Gb FC HBA mezzanine for BL460c?

[Cray]

Which slot should I insert the 4Gb FC HBA mezzanine in a BL460c for c3000? And, what will be different from slot 1 and slot 2?

According to c3000's port mapping, slot 1 connects only to bay 2. So, slot 2 will be better choice if I want to have a redundant SAN connectivity arch, right?

I have checked quickspec, SAN design guide, reference arch... etc and can't find a clear answer. THX in advance.

[JKytsi · Accepted solution]

You are correct, mezz slot2

Here is a neat pdf for info
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01167169/c01167169.pdf

[Cray]

Jarkko K,

Thanks.

In fact, I had read the pdf, too. But, there is no any exact keyword 'HBA', 'FC', 'Fiber' in the document?

[JKytsi]

yes ...because it does not matter if it's a FC or normal NIC. Only if You have quad port nics or infiniband HBA's there is a difference to use 4x or 8x slots.

[kris rombauts]

Cray,

even with the dual port FC MEZZ card in mezz slot 1 , you still have a redundant path from your server to your SAN via the interconnect in BAY 2 however all goes over the same interconnect, so if this interconnect fails then you loose the SAN access.

The advantage of putting the FC mezz card in mezz slot 2 is that you can have redundant access over a redundant interconnect if you invest into a second fibre interconnect module. If you don't then you only have one FC link to your SAN, keep that in mind.

So with the FC mezz in slot 1 , you have 2 links to the SAN over just one FC interconnect module, with the FC mezz in slot 2 you only have 2 links to the SAN if you buy a second FC interconnect.
You could always start with one FC interconnect and use dual path and if later it is needed/required to have more redundancy, move it to slot 2 and add a second FC interconnect. It might be a question of available budget also.


Kris