QDR Infiniband without a switch ?

[RimBlock]

I moved away from my DDR infiniband a while ago and, due to using a mITX san, ended up using iSCSI on a dedicated 1 GbE network but my OCD keeps nagging that I have 3 QDR cards sitting around.

I have just bought the bits for a new storage san (rack mount dual L5630s) and have a number of x8PCIe 2 slots available.

I am not in the market to drop $700 on a QDR switch with subnet manager so am looking at the options available to build a chained network with one of the nodes running a subnet manager.

What I am trying to find out is what configurations / max number of nodes etc is possible without a switch. Can you just chain machines together with dual port IB cards as long as one of the nodes is running a subnet manager or does the subnet manager have to have a direct link to the other nodes (either via a switch or directly attached via a cable) ?.

 

[vanfawx]

As far as I understand it, you can't daisy chain infiniband. It needs to be a hub configuration (central with spokes radiating outward), so your storage server with multiple HCA's connected point-to-point to your clients. Your storage server would be running the subnet manager as well.

Why don't you buy a QDR switch without a subnet manager and run that on any of your nodes?

 

[RimBlock]

Thanks for the info.

I just managed to get a Voltaire 4036 for just over $300 so hopefully that will resolve my issues.