How to Enable Debug Logging for Intel NICs Using the ixgben Driver in ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

In certain scenarios, NICs using the ixgben driver do not produce sufficient logs for effective troubleshooting.
By enabling debug-level logging, administrators can capture more detailed information when diagnosing NIC issues.

Environment

VMware vSphere ESXi

Cause

The ixgben driver can generate excessive log entries when debug logging is enabled, potentially flooding the kernel log.
Therefore, it is recommended to enable debug logging only when the issue is reproducible and further details are necessary for root cause analysis.

Resolution

Note: The following procedure is specific to the ixgben driver and is not persistent after a reboot

1. Identify the Target NIC Interface

Determine the vmnicX identifier for the NIC interface you want to monitor. Replace vmnicX in the commands below with the actual identifier (e.g., vmnic2).

2. Connect to the ESXi Host via SSH

Use an SSH client to connect to the ESXi host where the issue is observed.

3. Check the Current Debug Level

To check the current logging level for the NIC:

vsish -e get /net/pNics/vmnicX/genericOpts/messageLevel

4. Enable Debug Logging

To enable debug logging for the selected NIC:

vsish -e set /net/pNics/vmnicX/genericOpts/messageLevel 65



Once enabled, debug messages will be logged to /var/run/log/vmkernel.log. Example log entry:

[YYYY-MM-DDTHH:MM:SS] cpu10:2097387)ixgben: ixgben_SetMessageLevel:4364: vmnic2: Setting the Debug Flag : 0x00000000

5. Disable Debug Logging

After reproducing the issue and collecting logs, disable debug logging:

vsish -e set /net/pNics/vmnicX/genericOpts/messageLevel 0

Additional Information

 

• Debug logs are written to: /var/run/log/vmkernel.log and rotated logs (vmkernel.log.*)

• These settings are not persistent across reboots. Reapply them as needed after system restarts.