To start an individual test, select that test's button. Test parameters are on the same row as the test button.

For each of the tests, the run time can be specified in minutes (m), hours (h), or days (d). The default run time of 0 will run the test for one pass. Normally, the default values are good enough and won't need to be changed. However, in a large cluster solution, these values might need to be changed to reduce the load on CPUs or shorten the test time.

When a test is running, all test buttons are disabled (in grey color).

After each test, all nodes in the test are checked for disk and memory errors – the test fails if the error count exceeds the threshold.

The Network: pull-down is at the top of the interface. This is for selecting the cluster interconnect

type: Admin, Interconnect, or Alternate networks. The Admin network can be a GigE or 10GigE network, the Interconnect and Alternate networks may be GigE, InfiniBand, 10GigE, or None, if they have not been configured. For example, if you are testing an InfiniBand-based cluster with one IB connection per node, you will see Admin, and Interconnect-InfiniBand as options in the pull-down. If you are testing a dual-rail IB cluster, you will see Admin, Interconnect-InfiniBand, Alternate-InfiniBand, and Combined-InfiniBand. In this case, Interconnect-InfiniBand will test the first rail, Alternate-InfiniBand will test the second rail, and Combined-InfiniBand will use both rails for testing.

NOTE: Only MPI applications can use both rails for testing; the Ibverbs tests (ib_send_bw, ib_read_bw, etc.) and Netperf will only work on one rail at a time.

The Stop button halts the current test. When no test is running, this button is disabled.

The Test this group only check box allows tests to be run on either a group of nodes or on the whole cluster. If this box is checked, the tests will run on the group of nodes that includes the head node and compute nodes under its control. If this box is unchecked, the tests run on the whole cluster. When there is only one head node in the cluster solution, Test this group only has no effect.

8The Cluster Test GUI