KB 787224 - How to Collect Logs from NVIDIA Cumulus Linux Switch

Purpose

This article describes how to collect diagnostic logs from a switch running NVIDIA Cumulus Linux. These logs are typically required by NVIDIA Networking Support for troubleshooting switch-level issues such as port flaps, routing problems, fabric instability, or software faults.

Scope

This procedure applies to:

NVIDIA switches running Cumulus Linux
Environments using CLI (SSH) access to the switch
Scenarios requiring system, networking, and hardware diagnostics

Prerequisites

SSH access to the Cumulus Linux switch
Administrative (sudo) privileges

Procedure

Step 1: Log in to the Cumulus Linux Switch

Open a terminal.
Connect to the switch using SSH:

ssh cumulus@<switch-management-ip>

Elevate privileges if required:

sudo -i

Step 2: Verify Switch and OS Details (Optional but Recommended)

Collect basic system information:

        hostname
        cat /etc/os-release
         uname -a

Step 3: Generate Cumulus Support Log Bundle

Cumulus Linux provides a built-in command to collect comprehensive logs.

Run the following command:

sudo cl-support

This command:

Collects system logs
Captures network configuration
Gathers hardware and interface information
Packages everything into a compressed archive

The output file is typically generated under:

/var/support/

Step 4: Verify Log File Creation

Confirm the file exists and is non-empty:

ls -lh /var/support/

Step 5: Download log file

We can download the log file using an FTP tool like MobaXterm:

Log into the switch using MobaXterm
From the left tab go to path /var/support/
Locate the support file
Right click → Download
The support file will be downloaded into your system

Notes and Best Practices

Always run cl-support before rebooting the switch.
Do not modify the generated archive.
Ensure timestamps align with the reported incident.
Store log bundles securely, as they may contain sensitive configuration data.