You suspect bad links across an InfiniBand fabric. Which tool scans it for errors?
Why A is the answer
ibdiagnet
ibdiagnet scans the whole fabric and reports errors and topology problems.
In detail
- ibdiagnet scans an InfiniBand fabric for errors.
- It reports topology problems too.
Use case
An illustrative scenario, not a real incident.
Jobs slow on some paths, and ibdiagnet scans the fabric and reports bad links.
See it in different ways
flowchart TD
A{"What do you want to know?"} -->|"Local port state"| B["ibstat"]
A -->|"Which nodes exist"| C["ibnodes"]
A -->|"Link details"| D["iblinkinfo"]
A -->|"Fabric errors"| E["ibdiagnet"]
A -->|"RDMA speed"| F["ib_write_bw and ib_write_lat"]stateDiagram-v2 [*] --> LocalPort: ibstat LocalPort --> Fabric: ibnodes and iblinkinfo Fabric --> Errors: ibdiagnet Errors --> Path: ibping Path --> Speed: ib_write_bw and ib_write_lat Speed --> [*]
flowchart LR S0["Run ibdiagnet"] --> S1["Read the report"] --> S2["Fix the links"]
Key point: ibdiagnet scans the whole fabric.
Why the other options are wrong
- B. ethtool
- ethtool works on a single interface.
- C. netstat only
- netstat shows connections.
- D. ping only
- ping is not an InfiniBand fabric scan.