vMotion Performance Slowness and Timeouts: ESXi 8, bnxtnet Driver, and NIC Firmware Upgrades

Products

• VMware vCenter Server

Issue/Introduction

• vMotion performance issues and timeouts are observed following a server firmware upgrade involving ESXi with bnxtnet NIC driver/firmware.
•  TPA (Transmit/Receive Packet Aggregation) module is configured on the destination host.
• Small VMs may take up to 15 minutes to migrate, while larger VMs experience complete timeouts.
• Packet capture and log analysis indicate inconsistent migration times between hosts, with severely degraded vMotion network performance during specific host-to-host migrations.

Environment

VMware ESXi 8.0 Update 3J
bnxtnet driver
NIC firmware 232.1.132.8 to 237.1.148.0

Cause

The disable_tpa module parameter is set to a single integer (e.g., '0') instead of a comma-separated tuple that matches the host's physical NIC count.

Resolution

1. Identify the number of physical network ports controlled by the bnxtnet driver on the affected ESXi host (e.g., four NICs: vmnic0 through vmnic3).

2. Configure the disable_tpa module parameter within the bnxtnet driver explicitly using a tuple binary switch that matches the number of physical ports (e.g., a four-tuple configuration for four NICs).

3. Set the parameter to a comma separate list with a value or 0 or 1 for each port, e.g. (for four NICS: 1,1,1,1 to explicitly disable Transmit/Receive Packet Aggregation (TPA) across all four ports, or 0,0,0,0 to explicitly keep the feature active.) The values act as binary switches for each physical port where 1 disables the feature and 0 keeps it active.

Additional Information

See Download Broadcom products and software for steps to download compatible driver/firmware versions.