User Manual

OpenSM – Subnet ManagerRev 2.1-1.0.6
Mellanox Technologies
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eter for a dateline keyword moves the origin (and hence the dateline) the specified amount rela-
tive to the common switch in a torus seed.
If any of the switches used to specify a seed were to fail torus-2QoS would be unable to complete
topology discovery successfully. The next_seed keyword specifies that the following link and
dateline keywords apply to a new seed specification.
For maximum resiliency, no seed specification should share a switch with any other seed specifi-
cation. Multiple seed specifications should use dateline configuration to ensure that torus-2QoS
can grant path SL values that are constant, regardless of which seed was used to initiate topology
discovery.
portgroup_max_ports max_ports - This keyword specifies the maximum number of parallel
inter-switch links, and also the maximum number of host ports per switch, that torus-2QoS can
accommodate. The default value is 16. Torus-2QoS will log an error message during topology
discovery if this parameter needs to be increased. If this keyword appears multiple times, the last
instance prevails.
port_order p1 p2 p3 ... - This keyword specifies the order in which CA ports on a destination
switch are visited when computing routes. When the fabric contains switches connected with
multiple parallel links, routes are distributed in a round-robin fashion across such links, and so
changing the order that CA ports are visited changes the distribution of routes across such links.
This may be advantageous for some specific traffic patterns.
The default is to visit CA ports in increasing port order on destination switches. Duplicate values
in the list will be ignored.
EXAMPLE
next_seed
# Look for a 2D (since x radix is one) 4x5 torus.
torus 1 4 5
# y is radix-4 torus dimension, need both
# ym_link and yp_link configuration.
yp_link 0x200000 0x200005 # sw @ y=0,z=0 -> sw @ y=1,z=0
ym_link 0x200000 0x20000f # sw @ y=0,z=0 -> sw @ y=3,z=0
# z is not radix-4 torus dimension, only need one of
# zm_link or zp_link configuration.
zp_link 0x200000 0x200001 # sw @ y=0,z=0 -> sw @ y=0,z=1
next_seed
yp_link 0x20000b 0x200010 # sw @ y=2,z=1 -> sw @ y=3,z=1
ym_link 0x20000b 0x200006 # sw @ y=2,z=1 -> sw @ y=1,z=1
zp_link 0x20000b 0x20000c # sw @ y=2,z=1 -> sw @ y=2,z=2
y_dateline -2 # Move the dateline for this seed
z_dateline -1 # back to its original position.
# If OpenSM failover is configured, for maximum resiliency
# one instance should run on a host attached to a switch
# from the first seed, and another instance should run
# on a host attached to a switch from the second seed.
# Both instances should use this torus-2QoS.conf to ensure
# path SL values do not change in the event of SM failover.
# port_order defines the order on which the ports would be
# chosen for routing.
port_order 7 10 8 11 9 12 25 28 26 29 27 30