User Manual
OpenSM – Subnet ManagerRev 2.2-1.0.1
Mellanox Technologies
196
First Routing Engine in the Chain
The first unicast engine in a routing chain must include all switches and HCA's in the fabric
(topology id must be 0).
The path-bit parameter value is path-bit 0 and it cannot be changed.
Configuring a Routing Chains Policy
The routing chains policy file details the routing engines (and their fallback engines) used for the
fabric's routing.
The policy file should be composed of one or more paragraphs which defines an
engine (or a fallback engine). Each paragraph should begin with the line 'unicast-step' and end
with the line 'end-unicast-step'.
For example
unicast-step
…routing engine qualifiers…
end-unicast-step
:
Routing Engine Qualifiers
Unlike unicast-step and end-unicast-step which do not require a colon, all qualifiers must
end with a colon (':'). Also - a colon is a predefined mark that must not be used inside
qualifier values. An inclusion of a colon in the qualifier values will result in the policy's
failure.
Table 22 - Routing Engine Qualifiers
Parameter Description Example
id ‘id’ is mandatory. Without an id qualifier for
each engine, the policy fails.
• Legal values – size_t value (0 is illegal).
• The engines in the policy chain are set accord-
ing to an ascending id order, so it is highly cru-
cial to verify that the id that is given to the
engines match the order in which you would
like the engines to be set.
is: 1
engine This is a mandatory qualifier that describes
the routing algorithm used within this unicast
step.
Currently, on the first phase of routing chains,
legal values are minhop/ftree/updn.
engine: minhop
use This is an optional qualifier that enables one
to describe the usage of this unicast step. If
undefined, an empty string is used as a
default.
use: ftree routing for for
yellow stone nodes
config This is an optional qualifier that enables one
to define a separate opensm config file for a
specific unicast step. If undefined, all parame-
ters are taken from main opensm configura-
tion file.
config: /etc/config/
opensm2.cfg