Fat-Tree Topology Validation
This section specifies the options for Fat-Tree topology validation. Topology validation checks that the provided topology is a properly connected Fat-Tree topology. It detects tree structure, its “connectivity groups” and neighborhoods and their link issues. It also reports on a network theoretical “bisectional” bandwidth.
A newly generated output file – ibdiagnet2.fat_tree contains details about switches uplinks/downlinks issues and tree structure by levels. In a case FLIDs were applied on the network the output could contain warning if the same FLID appears in some neighborhoods.
Parameter | Description |
--ft | Provides a report of the fabric Fat-Tree analysis. Data will be dumped to the ibdiagnet2.fat_tree file. Warnings and errors will be dumped to the ibdiagnet2.log and ibdiagnet2.fat_tree files. |
--ft_roots_regex_opt | The regular expression to select Fat-Tree root nodes. Only nodes matching the regular expression will be taken as roots. |
--smdb <file> | Loads Fat-Tree roots from the subnet manager SMDB file (the routing engine reported in opensm-smdb.dump file should be one form the following list: “Fat-Tree”, Adaptive Routing Fat-Tree”, “UPDN”, “Adaptive Routing UPDN”). |
Example:
ibdiagnet –-ft
ibdiagnet's Output:
Fat-Tree Topology Validation -I- Fat-Tree topology detection finished successfully -I- 2 level Fat-Tree was discovered: rank: 0(Roots) #switches: 4 rank: 1 #switches: 4 -I- Fat-Tree topology validation finished successfully -E- For more errors see the dump file: ibdiagnet2.fat_tree -I- Calculated Fat-Tree bisectional bandwidth: 800.00 [Gb/s]
fat_tree file “connectivity groups”/neighborhoods and their switches uplinks/downlinks issues details:
-I- Neighborhood 0: all spines have the same number of downlinks: 4 -I- Neighborhood 0: all lines have the same number of uplinks: 4 -W- Neighborhood 0: lines with different number of downlinks (expected 4 downlinks) 2 downlinks: BM1-2 BM1-1
fat_tree file tree structure - switches by rank:
rank: 0 (Roots)size: 4 BM0-2 BM0-0 BM0-1 BM0-3 rank: 1 (Leaves)size: 4 BM1-0 BM1-2 BM1-1 BM1-3
fat_tree file tree structure – “connectivity groups”/neighborhoods by rank
on ranks (0, 1) -- neighborhoods: 1 neighborhood: 0 spines: 4 switches BM0-2 BM0-0 BM0-1 BM0-3 lines: 4 switches BM1-0 BM1-2 BM1-1 BM1-3
fat_tree file - the same FLID is found in some neighborhoods
-W- FLID=155 appears in the following neighborhoods: 1, 3