Fabric Manager Users Guide, Version 6.1, Revision A - QLogic

3–Fabric Manager Configuration
Configuring the QLogic Fabric Manager
The Fabric Manager constructs a spanning tree of the switches as part of the
dor-updown algorithm, and uses it as a basis for setting up the updown routes in
the fabric. If UpDownMcastSpanningTree parameter is set to 1, the updown
algorithm will use the same settings as the Multicast spanning tree
RootSelectionAlgorithm configuration parameter (in the Multicast section of
the configuration file) to build the updown spanning tree. Therefore, the updown
spanning tree and the multicast spanning tree will be similar. This will make sure
that the updown unicast traffic does not conflict with the multicast traffic and will
prevent credit loops. Another advantage is that the syncing of spanning tree root
between master Fabric Manager and stand-by Fabric Manager also applies to the
updown spanning tree root. If the RootSelectionAlgorithm is set to
LeastTotalCost or LeastWorstCaseCost, then updown routes will remain
the same on Fabric Manager failover (assuming there are no other major changes
in the fabric)
If UpDownMcastSameSpanningTree is set to 0, the updown spanning tree is
built independent of the multicast spanning tree settings. The switch running the
Embedded Fabric Manager or the switch next to the InfiniBand Adapter running
the master Host Fabric Manager is used as the root of the updown spanning tree.
Default value of UpDownMcastSameSpanningTree is 1.
As a consequence of using the same spanning tree for updown and multicast, the
multicast SL should match the dor-updown SL. The user can specify the SL in the
MulticastGroup configuration (which is used to create the default multicast groups
at startup). This SL is generally left unspecified and the SM has always used the
BaseSL of the associated VirtualFabric when creating the multicast groups.
Configuration checks are used to enforce use of the BaseSL. If the SL is
configured for a MulticastGroup and it does not match the BaseSL of the
associated VirtualFabric, an error will be logged and the group will be disabled.
The parameters in Table 3-5 control Mesh/Torus topology for Mesh/Torus fabrics.
Table 3-5. Sm Mesh/Torus Topology Parameters
PortPair
Parameter
Default
Value
Description
Specifies the Pair of switch ports which
will be connected between neighbor ports
in the given dimension. There must be 1
or more port pairs per dimension. Each
port pair defines a single ISL which will be
consistently cabled between all switches
in the dimension.
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