The InfiniBand connectivity between the nodes and the switches is dependent on the number of cabinets and nodes. Refer to the guidelines below, and the figures in subsequent sections.
UDA Inter-System Connections
The following guidelines apply to connections between the 2850 system and the UDA fabric.
- The number of UDA uplinks is based on a node-to-uplink ratio of 6:1, with a minimum of 3 uplinks.
- Uplinks are connected switch to switch.
- Connect the UDA uplinks as follows:
- For one- and two-cabinet systems, connect the UDA uplinks to the first-tier switch in cabinet 1.
- For systems with three or more cabinets, connect the UDA uplinks to the second-tier switch in cabinet 2.
- For systems with multiple second-tier switches, evenly distribute the UDA uplinks to the second-tier switches for best performance.
- UDA connections between systems start at the highest switch port on both systems, and connect in descending order.
For more information, see the Teradata Unified Data Architecture InfiniBand and Server Management Configuration Guide, B035-6001.
Appliance Intra-System Connections: Switch-to-Switch
The following guidelines apply to connectivity in the 2850 Appliance. (Refer to the diagrams in the following sections for examples and details.)
- Switch requirements:
- One-cabinet and two-cabinet systems use a single pair of base switches.
- Systems with three or more cabinets use first-tier switches and may also use second-tier switches.
- In a 3-cabinet system, to allow for expansion beyond 36 nodes or connection to UDA, the first-tier switches are installed in cabinets 1 and 3, and the second-tier switches are installed in cabinet 2.
- When 36-port, second-tier switches are installed, the first pair of second-tier switches reside in cabinet 2 and provide the second level of connection.
- In larger systems with additional pairs of second-tier switches, the second-tier switches reside in even-numbered cabinets.
- When second-tier switches are used, each pair of cabinets is considered a group, and the cabinets in the group connect to the same first-tier switches. The first-tier switches for the group then provide eight uplinks to the second-tier switch(es). The number of uplinks to each second-tier switch depends on the number of second-tier switches in use, which depends on the number of nodes and cabinets or clusters. Refer to the table for more information.
- Uplink connections start at the highest switch port number for the first-tier switch, and connect in ascending cabinet number to the second-tier switch, beginning with the first port.
| Number of Cabinets | Maximum Number of Nodes | Second-Tier Switches per Fabric | Uplinks (First-tier to Second-tier) Per Second-Tier Switch or Group |
|---|---|---|---|
| 1 to 2 cabinets | 24 nodes | None | None |
| 3 cabinets | 36 nodes | 1 | 8 |
| 4 to 8 cabinets | 96 nodes | 1 | 8 |
| 9 to 18 cabinets | 216 nodes | 2 | 4 |
| 19 to 36 cabinets | 432 nodes | 4 | 2 |
| 37 to 72 cabinets | 864 nodes | 8 | 1 |
Appliance Intra-System Connections: Node-to-Switch
The following general guidelines apply to connectivity in the 2850 Appliance. (Refer to the diagrams in the following sections for examples and details.)
- Intra-cabinet node-to-switch connections start with chassis 2 and switch port 1, and continue in ascending order.
- Inter-cabinet node-to-switch connections start with first available switch port after the intra-cabinet connections.
- Intra-cabinet connections use copper cables.
- Inter-cabinet connections use fiber cables.