Verify that all components on the vSphere network have their clocks synchronized. If the clocks on the physical machines in your vSphere network are not synchronized, SSL certificates and SAML Tokens, which are time-sensitive, might not be recognized as valid in communications between network machines.

Unsynchronized clocks can result in authentication problems, which can cause the installation to fail or prevent the vCenter Server vmware-vpxd service from starting.

Time inconsistencies in vSphere can cause firstboot to fail at different services depending on where in the environment time is not accurate and when the time is synchronized. Problems most commonly occur when the target ESXi host for the destination vCenter Server is not synchronized with NTP or PTP. Similarly, issues can arise if the destination vCenter Server migrates to an ESXi host set to a different time due to fully automated DRS.

To avoid time synchronization issues, ensure that the following is correct before installing, migrating, or upgrading a vCenter Server.
  • The target ESXi host where the destination vCenter Server is to be deployed is synchronized to NTP or PTP.
  • The ESXi host running the source vCenter Server is synchronized to NTP or PTP.
  • When upgrading or migrating from vSphere 6.5 or 6.7 to vSphere 7.0, if the vCenter Server appliance is connected to an external Platform Services Controller, ensure the ESXi host running the external Platform Services Controller is synchronized to NTP or PTP.
  • If you are upgrading or migrating from vSphere 6.5 or 6.7 to vSphere 7.0, verify that the source vCenter Server or vCenter Server appliance and external Platform Services Controller have the correct time.
  • When you upgrade a vCenter Server 6.5 or 6.7 instance with an external Platform Services Controller to vSphere 7.0, the upgrade process converts to a vCenter Server instance with an embedded Platform Services Controller.

Verify that any Windows host machine on which vCenter Server runs is synchronized with the Network Time Server (NTP) server. See the VMware knowledge base article at

To synchronize ESXi clocks with an NTP server or a PTP server, you can use the VMware Host Client. For information about editing the time configuration of an ESXi host, see vSphere Single Host Management - VMware Host Client.

To learn how to change time synchronization settings for vCenter Server, see "Configure the System Time Zone and Time Synchronization Settings" in vCenter Server Configuration.

To learn how to edit time configuration for a host by using the vSphere Client, see "Editing Time Configuration for a Host" in vCenter Server and Host Management.