ESXi 8.x Upgrade Causes vmnic PCI Mapping Inconsistency and Network Loss

Products

• VMware vSphere ESXi

Issue/Introduction

Following an upgrade of ESXi hosts, the physical-to-logical mapping of network interface cards (vmnics) becomes inconsistent.

- Symptoms include a loss of storage connectivity and the inability to migrate virtual machines.

- Diagnostic commands indicate that PCI bus addresses are incorrectly mapped to logical vmnic aliases.

Environment

VMware ESXi 7.x
VMware ESXi 8.x

Cause

 VMware ESXi 8.x determines the naming order for network devices during an upgrade or fresh installation. This causes a re-enumeration of vmnic IDs where physical PCI devices are assigned different logical identifiers than those previously configured in the 7.x environment.

- For Cisco UCS environments, this can occur after adding the new NICs to the hosts or upgrading the ESXi hosts. 

Resolution

To resolve this issue please follow this KB: 

How VMware ESXi determines the order in which names are assigned to the devices