User Manual

OpenSM – Subnet ManagerRev 2.1-1.0.6
Mellanox Technologies
138
8 OpenSM – Subnet Manager
8.1 Overview
OpenSM is an InfiniBand compliant Subnet Manager (SM). It is provided as a fixed flow execut-
able called opensm, accompanied by a testing application called osmtest. OpenSM implements
an InfiniBand compliant SM according to the InfiniBand Architecture Specification chapters:
Management Model (13), Subnet Management (14), and Subnet Administration (15).
8.2 opensm Description
opensm is an InfiniBand compliant Subnet Manager and Subnet Administrator that runs on top of
the Mellanox OFED stack.
opensm performs the InfiniBand specification’s required tasks for ini-
tializing InfiniBand hardware. One SM must be running for each InfiniBand subnet.
opensm also provides an experimental version of a performance manager.
opensm defaults were designed to meet the common case usage on clusters with up to a few hun-
dred nodes. Thus, in this default mode,
opensm will scan the IB fabric, initialize it, and sweep
occasionally for changes.
opensm attaches to a specific IB port on the local machine and configures only the fabric con-
nected to it. (If the local machine has other IB ports,
opensm will ignore the fabrics connected to
those other ports). If no port is specified,
opensm will select the first “best” available port.
opensm can also present the available ports and prompt for a port number to attach to.
By default, the
opensm run is logged to two files: /var/log/messages and /var/log/
opensm.log. The first file will register only general major events, whereas the second file will
include details of reported errors. All errors reported in this second file should be treated as indi-
cators of IB fabric health issues. (Note that when a fatal and non-recoverable error occurs,
opensm will exit). Both log files should include the message "SUBNET UP" if opensm was able
to setup the subnet correctly.
8.2.1 opensm Syntax
opensm [OPTIONS]
where OPTIONS are:
--version
Prints OpenSM version and exits.
--config, -F <file-name>
The name of the OpenSM config file. When not specified
/etc/opensm/opensm.conf will be used (if exists).
--create-config, -c <file-name>
OpenSM will dump its configuration to the specified file and exit.
This is a way to generate OpenSM configuration file template.
--guid, -g <GUID in hex>
This option specifies the local port GUID value
with which OpenSM should bind. OpenSM may be