VM Guest OS System Time Unexpectedly Changes Due to VMware Tools - VMware vSphere

Products

• VMware vSphere ESX 8.x

Issue/Introduction

Introduction

Windows virtual machines may experience unexpected system clock drifts or jumps, often manifesting as 1- or 2-hour discrepancies. In time-sensitive environments, such as those running Microsoft SQL Server, these clock shifts can cause scheduled jobs to fail or skip execution. This issue is typically caused by a configuration mismatch involving the vmwTimeProvider plugin.

 

Symptoms

• Scheduled jobs in afflicted VMs' guest OS systems do not fire at expected times or fail due to "already ran" logic discrepancies.
• A Windows VM may have its system time reconfigured to a different time (e.g. 2 hours back).
• VM's vmware.log file shows where clock reads fail:
  • Ex: 2026-01-01T3:00:00.000Z In(05) vcpu-1 - Guest: [vmwTimeProvider][warn] TimeProvOpen: Failed to read from clock 0
• When viewing the Windows Event Viewer for the VM within the guest OS, there are Kernel-General information events similar to the following:
  • The system time has changed to 2026-01-01T1:00:00.000000000Z from 2026-01-01T3:00:00.000000000Z.
  • Change Reason: An application or system component changed the time.
  • Process: '\Device\HarddiskVolume1\Program Files\VMware\VMware Tools\vmtoolsd.exe' (PID 1234).

Environment

vSphere ESX 8.x

VMware Tools 12.x

VMware Tools 13.x

Windows 10

Windows 11

Cause

This issue can occur when the vmwTimeProvider component is installed during the VMware Tools installation process, but the virtual machine lacks the required "Precision Clock" virtual hardware device. Because the plugin attempts to sync time with a non-existent hardware device, it conflicts with the native Windows Time service (W32Time), leading to time synchronization instability.

Resolution

The following procedures describe how to remediate the vmwTimeProvider conflict. For comprehensive technical background and additional troubleshooting context, refer to "Microsoft-Windows-Time-Service message: The time provider 'vmwTimeProvider' logged the following error: A precision clock device was not found".

 

Choose one of the following two options, based on your desired time synchronization source:

Option 1: Uninstall the VMware Time Provider (Recommended for NTP/AD Users)

Use this option if your environment utilizes Active Directory or an external NTP server for time synchronization.

1. Disable Autorun on the Windows Guest OS:
   1. Select the Start icon, then the Settings icon.
   2. Select Devices.
   3. Select AutoPlay from the left pane, then toggle the AutoPlay switch to Off.
2. Mount the current VMware Tools ISO to the virtual CD/DVD drive via the vSphere Client Edit Settings menu.
3. Run the installer inside the Guest OS and select Modify installation.
   • Note: If Autorun is disabled, manually launch D:\setup.exe (where D is the CD-ROM drive).
4. Navigate the wizard to the VMware Time Provider feature and select Entire feature will be unavailable.
5. Click Next and Finish.
6. Reboot the VM to apply the changes.

Option 2: Add a Precision Clock Device (Recommended for Host Sync)

Use this option if your VM requires time synchronization directly with the ESXi host.

1. Ensure the VM Hardware Version is 17 or higher.
2. Open the VM Edit Settings menu in vSphere.
3. Add the Precision Clock hardware device.
4. Restart the Windows Time service (W32Time) within the Guest OS.

Additional Information

For further documentation on VMware Tools, see VMware Tools Administration.