Before you deploy the vCenter Server Appliance, make sure all machines on the network have their clocks synchronized. Unsynchronized clocks can cause installation and authentication errors.

On systems that are joined to a Windows domain, the vCenter Server Appliance clock is synchronized automatically with the domain controller. On other systems, you can enable synchronizing the clock through VMware Tools. As an alternative, you can use this procedure.


  1. Open a Web browser and navigate to the vCenter Server Appliance Management Interface (https://vCenter-Appliance-IP-Address:5480/).
  2. Log in as root.
  3. From the vCenter Server tab, select the Time subtab.
  4. Select one or more of the available options.
    Option Description
    No synchronization Does not perform synchronization.
    NTP synchronization Select this option and specify one or more NTP servers to configure the appliance to synchronize with an NTP server directly.
    VMware Tools synchronization Select this option to synchronize all virtual machines.
    Active Directory synchronization This option becomes available only if you add the appliance to an Active Directory domain. If you select this option, none of the other options is available.
  5. Click Save Settings.


The vCenter Server Appliance clock is synchronized with the NTP server.