A Precision Clock device is a virtual clock device that provides a virtual machine with access to the system time of the primary ESXi host.
To synchronize the guest operating system of a virtual machine with the host in an efficient manner, add a Precision Clock device to the virtual machine. For information on how to use the Precision Clock device as a reference clock for time synchronization of the supported guest operating system, see the vCenter Server and Host Management documentation.
- To ensure that the Precision Clock device provides the guest operating system of a virtual machine with accurate time, synchronize the primary ESXi host to use Network Time Protocol (NTP) or Precision Time Protocol (PTP). For information how to configure the host time synchronization, see the vSphere Single Host Management - VMware Host Client documentation.
- Power off the virtual machine.
- Verify that the virtual machine hardware is of version 17.
- Required privileges:
- Right-click a virtual machine from the vSphere Client inventory and select Edit Settings.
- On the Virtual Hardware tab, click Add New Device, and from the drop-down menu select Precision Clock.
The Precision Clock device appears in the Virtual Hardware devices list.
- Select the time synchronization protocol and click OK.
Option Description Any The ESXi host time synchronization type has no limitations. NTP You can power on the virtual machine on an ESXi host that is configured with NTP time synchronization. PTP You can power on the virtual machine on an ESXi host that is configured with PTP time synchronization.