[lustre-discuss] Multi-cluster (multi-rail) setup

[Thrash Er]

New to Lustre O:)

I have to install and configure a Lustre storage for 4 small clusters
(4 different departments). Each cluster has its own IB QDR
interconnect for MPI (and now Lustre) and its own 1 GigE management
network. IB networks would be something like:
     Cluster A      192.168.1.0      o2ib0(ib0)
     Cluster B      192.168.2.0      o2ib1(ib1)
     Cluster C      192.168.3.0      o2ib2(ib2)
     Cluster D      192.168.4.0      o2ib3(ib3)

I've gone through the Lustre Operations Manual 2.x and, from what I
understood, I would have to:

1.- add 4 IB ports to each OSS and MDS/MGT and cable them like this:
     IB Port 0 -> cluster A
     IB Port 1 -> cluster B
     IB Port 2 -> cluster C
     IB Port 3 -> cluster D

2.- configure /etc/modprobe.d/lustre.conf on the OSS and MDS like this:

     options lnet networks="o2ib0(ib0),o2ib1(ib1),o2ib2(ib2),o2ib3(ib3)"

3.- configure /etc/modprobe.d/lustre.conf on each node of each cluster
like this:

     Nodes con Cluster A:      options lnet networks="o2ib0(ib0)"

     Nodes con Cluster B:      options lnet networks="o2ib1(ib1)"

     Nodes con Cluster C:      options lnet networks="o2ib2(ib2)"

     Nodes con Cluster D:      options lnet networks="o2ib3(ib3)"


Soooo, questions:
   1.- Are my assumptions correct?
   2.- No need for LNET routers, right?
   3.- Am I missing something?

Thanks !!!!!!