Home Switchboard Unix Administration Red Hat TCP/IP Networks Neoliberalism Toxic Managers
May the source be with you, but remember the KISS principle ;-)
Bigger doesn't imply better. Bigger often is a sign of obesity, of lost control, of overcomplexity, of cancerous cells

InfiniBand Subnet Manager


High Performance Computing (HPC)

 Recommended Links

Mellanox OpenFabrics Enterprise Distribution for Linux (MLNX_OFED)

Installing Mellanox InfiniBand Driver on RHEL 6.5

Setting up a basic infiniband network Getting Started with InfiniBand InfiniBand Subnet Manager
Mellanox InfiniBand switch ConnectX-3 cards GPFS on Red Hat HPC cluster architecture Message Passing Interface     Oracle Grid Engine
  Troubleshooting InfiniBand connection issues using OFED tools Linux Troubleshooting Linux Troubleshooting Tips Network Performance tuning Linux Performance Tuning Admin Horror Stories Humor Etc

Submitted by Peter Hartman (... on

The InfiniBand subnet manager (OpenSM) assigns Local IDentifiers (LIDs) to each port connected to the InfiniBand fabric, and develops a routing table based off of the assigned LIDs.

There are two types of subnet managers, software based and hardware based. Hardware based subnet managers are typically part of the firmware of the attached InfiniBand switch. A software subnet manager is not necessary if a hardware based subnet manager is active.

A typical InfiniBand installation using the OFED package will run the OpenSM subnet manager at system start up after the OpenIB drivers are loaded. This automatic OpenSM is resident in memory, and sweeps the InfiniBand fabric approximately every 5 seconds for new InfiniBand adapters to add to the subnet routing tables. This usage will be sufficient for most installations, and can be controlled using the following commands:

/etc/init.d/opensmd start
/etc/init.d/opensmd stop
/etc/init.d/opensmd restart
/etc/init.d/opensmd status
There are several instances where the default usage will not be sufficient, however. If the head node is used as a compute node, and resources are at a premium, the OpenSM subnet manager can be set to run once, configure the LIDs and routing tables, and then exit:
opensm -o
For InfiniBand adapters with two ports, a second instance of the subnet manager must be active to enable a subnet on the second port. To begin, enable the subnet manager as above:
service opensmd start
service opensmd start
Starting IB Subnet Manager.                                [  OK  ]
# ibstat
CA 'mlx4_0'
        CA type: MT4099
        Number of ports: 1
        Firmware version: 2.30.8000
        Hardware version: 1
        Node GUID: 0x0002c90300b78240
        System image GUID: 0x0002c90300b78243
        Port 1:
                State: Active
                Physical state: LinkUp
                Rate: 40 (FDR10)
                Base lid: 1
                LMC: 0
                SM lid: 1
                Capability mask: 0x0251486a
                Port GUID: 0x0002c90300b78241
                Link layer: InfiniBand

If we have two ports we need to  discover the GUID of the second port:

ibstat -p
This command will output two numbers, one for each port. Use the second number to start up a new OpenSM instance in daemon mode:
opensm -g <0xguid number> -B
There may also be an instance where the head node does not have InfiniBand hardware, but the compute nodes do. In this case, provided a hardware subnet manager is not used, one of the compute nodes must act as the subnet manager.

If there is already a subnet manager is running on the cluster, either a hardware based version or an OpenSM instance, then running OpenSM on another node will cause the new instance to be put in a STANDBY state. In this state, the instance listens for the existing OpenSM instance to fail, and will take over subnet manager duties once a failure state has been detected.

Recommended Links

Google matched content

Softpanorama Recommended

Top articles


Top articles


Intel® Cluster Ready



Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy


War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotesSomerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose BierceBernard Shaw : Mark Twain Quotes


Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law


Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOSProgramming Languages History : PL/1 : Simula 67 : C : History of GCC developmentScripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-MonthHow to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D

Copyright © 1996-2018 by Dr. Nikolai Bezroukov. was initially created as a service to the (now defunct) UN Sustainable Development Networking Programme (SDNP) in the author free time and without any remuneration. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.

FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.

This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...

You can use PayPal to make a contribution, supporting development of this site and speed up access. In case is down you can use the at


The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the author present and former employers, SDNP or any other organization the author may be associated with. We do not warrant the correctness of the information provided or its fitness for any purpose.

The site uses AdSense so you need to be aware of Google privacy policy. You you do not want to be tracked by Google please disable Javascript for this site. This site is perfectly usable without Javascript.

Last modified: