[Full Guide] How to perform vCenter NTP Configuration

vCenter NTP configuration directly impacts performance in virtualized environments. By ensuring accurate timekeeping, you can enhance performance, troubleshoot effectively, and maintain the overall stability and reliability of your virtual infrastructure.


By Zelia / Updated on September 5, 2023

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What is NTP

Network Time Protocol (NTP) is a networking protocol widely used in computer systems and networks to synchronize the time of devices within a network. NTP is designed to ensure that all the devices connected to a network maintain accurate and consistent time, which is crucial for various applications and services that rely on synchronized time.

NTP operates based on a hierarchical system of time servers, where higher-stratum servers are more accurate and reliable sources of time, and lower-stratum servers synchronize their time with higher-stratum servers. The most accurate time sources are typically atomic clocks and GPS receivers.


How to configure vCenter Server to use NTP server

Configuring VMware vCenter Server to use an NTP (Network Time Protocol) server is essential for maintaining accurate and synchronized time in your virtualized environment. Here's a step-by-step guide on how to configure vCenter NTP server in vCenter:

1. Open a web browser and access the vCenter Server Appliance Web Console (VAMI) using the following URL:


2. Log in as root.


3. Select Time to let v Center set time manually and proceed to Time Synchronization. Then click Edit.


4. In the Mode section, select NTP.


5. Enter the NTP server(s)on Time servers and save your changes by clicking SAVE.


How to add or replace NTP Server in vCenter Server Configuration

Adding or replacing NTP (Network Time Protocol) servers in the vCenter Server configuration is essential to ensure accurate and synchronized timekeeping within your virtualized environment. Here are the steps to configure NTP vCenter server appliance:

1. Access the appliance shell and log in using an account with either the administrator or super administrator role, with the default super administrator being "root."

2. To add NTP servers into the vCenter Server configuration, execute the following ntp.set command:

ntp.set --servers IP-addresses-or-host-names

Note: In this command, "IP-addresses-or-host-names" denotes a list of IP addresses or host names of NTP servers, separated by commas.

This command replaces any existing NTP servers with the new ones specified, and if time synchronization relies on an NTP server, it triggers a restart of the NTP daemon to load the updated servers.

3. (Optional) To confirm the successful application of the new NTP configuration settings, use the following command:


This command provides a space-separated list of the servers configured for NTP synchronization. If NTP synchronization is enabled, the command indicates that the NTP configuration is in an "Up" status; otherwise, it reports a "Down" status.

4. (Optional) For checking the reachability of NTP servers, run the following command:

ntp.test --servers IP-addresses-or-host-names

The command provides the status of the NTP servers.

Reliable and secure solution for vCenter VMs backup and restore

While vCenter NTP configuration is crucial for timekeeping, safeguarding your vCenter Server and its associated virtual machines requires reliable backup and restore solutions.

Therefore, I would like to introduce a VMware backup software – AOMEI Cyber Backup. With its emphasis on data security, efficiency, and ease of use, it empowers you to protect your virtualized environments effectively, ensuring that critical VMs remain available and recoverable even in the face of unexpected challenges.

◆ Centralized Backup:Create a backup task for multiple VMs without installing agent on each of them.
◆ Support Free ESXi: Support both paid and free versions of VMware ESXi.
◆ Various Backup Methods: Besides full backup, you can perform incremental or differential VM backup to capture only changed data and save storage space.
◆ Restore from Any Point: Restore a whole VM to usable state from any history backup version.
◆ Automated Hot Backup: Auto backup running VMs and notify via email.

AOMEI Cyber Backup supports VMware ESXi 6.0 and later versions. Here I will demonstrate how to backup VMware ESXi VMs and then restore them with ease. Click the following button to download the 30-day free trial.

Download Free TrialVMware ESXi & Hyper-V
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*You can choose to install this VM backup software on either Windows or Linux system.

Steps to perform VMware VMs backup and restore

1. Bind Devices: Access to AOMEI Cyber Backup web client, navigate to Source Device >> VMware >> + Add VMware Device to Add vCenter or Standalone ESXi host. And then click >> Bind Device.


2. Create Backup Task: Navigate to Backup Task >> + Create New Task >> Backup Type >> VMware ESXi Backup and set Task Name, Device, Target, Schedule, and Cleanup as needed.

  • Schedule (optional): Perform full, differential, or incremental backup, and automate execution according to the frequency you specified.


  • Device: Batch select large numbers of VMs managed by vCenter Server for centralized backup.


  • Cleanup (optional): Automatically delete the old backup copies that exceed the retention period you specified.


3. Run Backup: Click Start Backup and select Add the schedule and start backup now, or Add the schedule only.


4. Restore Task: When restoring, you can also restore to new location to create a new VM in the same or another datastore/host directly from the backup, saving the trouble of re-configuring the new VM.



vCenter NTP configuration is essential for maintaining accurate time synchronization in your vSphere environment. Regularly updating and securing your NTP server configurations ensures that your virtualized infrastructure operates smoothly.

Additionally, investing in a reliable and secure backup and restore solution for VMware VMs safeguards your data and enhances your overall disaster recovery strategy. Accurate timekeeping and robust data protection are fundamental pillars in building a resilient and efficient virtualized environment.

Zelia · Editor
Zelia is an editor from AOMEI Technology.She mainly writes articles about virtual machine. Writing is one of her hobbies and she wants her articles to be seen by more people. In her spare time, she likes to draw and listen to music, and it is a pleasure for her to focus on her own world.