VCF Deployment Validation Fails with an 'Error: Failed to validate NFS configuration (NFS Error 0x301)'

Products

• VMware SDDC Manager / VCF Installer

Issue/Introduction

• VCF deployment fails during the validation stage at the Cloud Builder wizard. The ESXi host (e.g., <host FQDN>) cannot establish a stable connection to the NFS Server (<NFS IP>).
• The following error is reported in the VCF Installer: Error: Failed to validate NFS configuration... Service NFS on port: 111, IP: <NFS IP> is not running: error:22

Environment

• VCF 9.x

Cause

The issue is caused by network MTU misconfiguration resulting in 9000-byte Jumbo Frame packet drops and an unreachable NFS RPC Bind service on Port 111, leading to storage connectivity validation failures.

Resolution

To resolve this issue, ensure the network and storage environments are aligned using the following steps:

1. Align Network MTU Configuration

Every link in the communication path must support 9000 MTU for Jumbo Frames to function:

• ESXi VMkernel Interface: Update vmk1 on all hosts to MTU 9000.
• Virtual Switch: Set the Virtual Standard Switch (vSwitch) or Distributed Switch (vDS) handling storage traffic to MTU 9000.
• Physical Infrastructure: Update physical switch ports, VLANs, and trunks to support Jumbo Frames (typically 9000 or 9216 MTU).

2. Verify NFS Server & Port Accessibility

• Confirm the NFS service daemon is active on the storage array.
• Verify NFS Export Rules/ACLs permit access to the ESXi storage VMkernel adapter IPs.
• Ensure firewalls allow TCP/UDP ports 111 (RPC Bind) and 2049 (NFS).

3. Final Validation

Run the following command from the ESXi CLI to verify connectivity:

vmkping -I vmk1 192.168.181.1 -s 8972 -d -c 3

Once you achieve 0% packet loss, click Re-Validate in the VCF wizard to proceed.