Guest OS customization fails when deploying Windows Server 2025 with 1 vCPU

Products

• VMware Cloud Director

Issue/Introduction

In VMware Cloud Director (VCD), when deploying a Windows Server 2025 virtual machine with the vCPU configured to 1 core, Guest OS Customization may fail to complete successfully.

• The OS boots without applying settings such as IP address, hostname, or SID changes.
• When the same VM is deployed or reconfigured with 2 or more vCPUs, the customization completes successfully using the same template and procedures.
• The guestcust.log file (located in C:\Windows\Temp\vmware-imc\) contains the following error:
  [YYYY-MM-DDThh:mm:ss: INFO] Executing command: 'netsh interface ip set address # static xxx.xxx.xxx.xxx 255.255.255.0 xxx.xxx.xxx.xxx 1'
[YYYY-MM-DDThh:mm:ss: WARN] Command execution failed with exit code: 1, output: 'Element not found.'

Environment

VMware Cloud Director 10.6

Cause

This issue is caused by a timing issue (race condition) resulting from insufficient CPU resources during the initial OS boot.

When only 1 vCPU is assigned, the VMware Tools customization process may trigger before the Windows OS has finished identifying the NIC hardware and loading the necessary network drivers.

Consequently, the netsh command fails because the target network interface is not yet available in the OS.

Resolution

To resolve this issue, increase the virtual machine's resource allocation:

• Configure the virtual machine with 2 or more vCPUs.
  Increasing the number of vCPUs helps the OS initialization process go more smoothly, ensuring that the NICs are properly recognized before the customization process attempts to configure the network settings.

Additional Information

Windows Server 2025 を vCPU 1 コアでデプロイするとゲスト OS のカスタマイズが失敗する