User guide

3–InfiniBand
®
Cluster Setup and Administration
Checking Cluster and Software Status
3-44 IB0054606-02 A
5. Finally, test by logging into the front end node, and from the front end node
to a compute node, as follows:
$ ssh frontend_node_name
$ ssh compute_node_name
For more information, see the man pages for ssh(1), ssh-keygen(1),
ssh-add(1), and ssh-agent(1).
Process Limitation with ssh
Process limitation with ssh is primarily an issue when using the mpirun option
-distributed=off. The default setting is now -distributed=on; therefore, in
most cases,
ssh process limitations will not be encountered. This limitation for the
-distributed=off case is described in the following paragraph.
MPI jobs that use more than 10 processes per node may encounter an
ssh
throttling mechanism that limits the amount of concurrent per-node connections
to 10. If you need to use more processes, you or your system administrator must
increase the value of
MaxStartups in your /etc/ssh/sshd_config file.
Checking Cluster and Software Status
ipath_control
IB status, link speed, and PCIe bus width can be checked by running the program
ipath_control. Sample usage and output are as follows:
$ ipath_control -iv
QLogic OFED.VERSION yyyy_mm_dd.hh_mm_ss
0: Version: ChipABI VERSION, InfiniPath_QLE7340, InfiniPath1
VERSION, SW Compat 2
0: Serial: RIB0935M31511 LocalBus: PCIe,5000MHz,x8
0,1: Status: 0xe1 Initted Present IB_link_up IB_configured
0,1: LID=0x23 GUID=0011:7500:005a:6ad0
0,1: HRTBT:Auto LINK:40 Gb/sec (4X QDR)