In Dell EMC PowerScale systems that use InfiniBand for back-end networking, the cabling standards are specific to ensure optimal performance and compatibility.

InfiniBand Cable Support:

QSFP to QSFP Cabling Only:

QSFP (Quad Small Form-factor Pluggable):

A compact, hot-pluggable transceiver used for high-speed InfiniBand networking.

Standard for PowerScale:

PowerScale systems utilizing InfiniBand support QSFP to QSFP cables exclusively.

Ensures high-bandwidth, low-latency communication between nodes.

Why Option A is Correct:

Exclusive Support:

QSFP to QSFP is the only supported cabling method for InfiniBand in these systems.

Compatibility and Performance:

Using QSFP to QSFP cables guarantees compatibility with node interfaces and optimal network performance.

Why Other Options Are Incorrect:

Option B (QSFP to QSFP or QSFP to CX4):

QSFP to CX4 is not supported; CX4 is an older connector type not compatible with current PowerScale InfiniBand configurations.

Option C (QSFP to CX4 only):

Incorrect, as QSFP to CX4 cabling is not used in PowerScale systems for InfiniBand.

Option D (Supports front-end customer external traffic):

InfiniBand is used for internal back-end networking, not for front-end external customer traffic, which uses Ethernet connections.

Dell PowerScale References:

Dell EMC PowerScale Networking Guide:

Back-End Network Cabling Section:

Specifies the use of QSFP to QSFP cables for InfiniBand connectivity.

Supported Cable Types:

Lists the approved cables and transceivers for InfiniBand networks.

Hardware Installation Guides:

Provide detailed instructions and diagrams for cabling using QSFP to QSFP connections.

Best Practices:

Use Certified Cables:

Always use Dell EMC-approved QSFP to QSFP cables to ensure reliability.

Proper Installation:

Follow the recommended procedures for connecting and securing InfiniBand cables.

Cable Management:

Organize cables to prevent strain and maintain proper airflow.

Additional Notes:

InfiniBand Usage:

Provides high-speed communication between nodes for data replication and cluster operations.

Transition to Ethernet:

Newer PowerScale models may use Ethernet back-end networking instead of InfiniBand.