[ofa-general] RE: minimum sw components requirement for driver/opensm in a single unmanaged switch network

[Sean Hefty]

> I have a IB network which consists of only a single unmanaged switch,
> all end nodes connecting with the switch only need to do RDMA
> read/write operation with each other. My question is, what are the
> indispensable modules in driver's core and opensm that make the 
> network up and run? 

The opensm node requires ib_core, ib_mad, ib_umad, and ib_mthca.

The other nodes require ib_core, ib_mad, ib_mthca, plus others,
depending on you application.  If it is a userspace application, then
you need ib_uverbs as well.

> I've been using only ib_mad module in driver's core with a managed
> switch before, and the network works fine. So I assume that only the
> ib_mad module in driver's core and SM in opensm are mandatory in my
> network. The LIDs are assigned by them. The SA and CM modules are not
> useful in my case. Am I right? 

You need to establish connections between the nodes, and configure the
QPs.  The QP number and LID information must be exchanged between the
various nodes somehow (over a socket connection, manually entered into
each application, user-defined MADs, whatever).  If the machines also
connect into an Ethernet network, you could exchange the data over
sockets.

- Sean