LNet selftest is a utility application that is used to verify LNet configuration and measure performance of the connection between a set of machines.

It is described in the public wiki here: http://wiki.lustre.org/LNET_Selftest

This page lists several peculiarities of the selftest utility not mentioned on the public wiki, either because they are results of bugs in the utility or because the official page is lagging behind in updates.

MR Configuration

Discovery

If nodes involved in selftest are multi-rail, discovery command needs to be run manually before the test is started: 

It should be enough to run this command once for every pair of nodes as they are supposed to exchange information.

Using Primary NIDs

When configuring selftest for testing connection between MR nodes, it is currently important to identify each node with nid that is assigned as "primary".

Running the command above shall list the peers and corresponding nids, specifying which nid is "primary".