Verifying time synchronization across an ESX/ESXi host environment

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

This article guides you through the process of verifying that the time for hosts in your environment are synchronized.

Environment

VMware vCenter Server 5.0.x
VMware vCenter Server 5.1.x
VMware vCenter Server 5.5.x
VMware vSphere ESXi 5.0
VMware VirtualCenter 2.5.x
VMware vCenter Server 4.0.x
VMware ESXi 4.0.x Embedded
VMware vSphere ESXi 6.5
VMware vSphere ESXi 5.1
VMware ESXi 3.5.x Embedded
VMware vCenter Server 4.1.x
VMware vSphere ESXi 6.7
VMware ESXi 4.1.x Installable
VMware VirtualCenter 2.0.x
VMware ESXi 3.5.x Installable
VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 6.0
VMware ESX 4.1.x
VMware ESX Server 3.5.x
VMware vSphere ESXi 5.5
VMware ESX 4.0.x
VMware ESX Server 3.0.x
VMware ESXi 4.0.x Installable

Resolution

Verifying time on VMware ESX

1. To verify the time on an ESX host, enter this command from the ESX host command line. Ensure that the correct time zone and date are displayed:
   
   # date
   
   Note: For adjusting the time zone, see Adjusting ESX Server Time Zone (1436).
    
2. Verify the time set in the hardware BIOS of the ESX/ESXi host if this host is experiencing difficulty keeping time, despite it having its time correctly set and successfully connected to running and correctly configured NTP server.

 

Synchronizing time on VMware ESX

The time must be synchronized if there are time discrepancies in the environment. The time can be set manually or maintained by using a Network Time Protocol (NTP) server. For synchronizing time using NTP, see Installing and Configuring NTP on VMware ESX Server (1339)or Guide to configure NTP on ESX servers (1003063).

 

 

To set the time from the ESX command line manually, use the date -s command. For example, to set the date to 31 Jan 2012 18:00:00, type this command as the root user:

# date -s "31 Jan 2012 18:00:00"

To set the time from vSphere Client:

1. Launch vSphere Client.
2. Go to Configuration > Time Configuration > Properties.
3. Input the correct Time and Date.
4. Click Options.
5. Click Restart on the Service Commands box.

Synchronizing time on VMware ESXi

The time must be synchronized if there are time discrepancies in the environment. The time can be set manually or maintained by using a Network Time Protocol (NTP) server. For synchronizing time using NTP, see Configuring Network Time Protocol (NTP) on ESX/ESXi hosts using the vSphere Client (2012069).

For ESXi 6.x refer to VMware Documentation

 

 

As of vSphere 4.1, hosts are set to UTC. When running the below esxcli command, set it to UTC, not local time zone. For more information, see Adjusting ESX host Time Zone (1436). The vSphere Client and vSphere Web Client automatically display time in your local Time Zone and will take into account UTC setting on host(s).

 

To set the time from the ESXi command line manually, use the esxcli system time set command. For example, to set the date to 31 Jan 2012 18:00:00 UTC, type this command as the root user:

# esxcli system time set -d 31 -M 1 -y 2012 -H 18 -m 0 -s 0

If this is not just a temporary measure to connect to an existing server, but needs to hold through reboots, then set the hardware clock to the same time as well:

# esxcli hardware clock set -d <day> -H <hour> -m <minutes> -s <seconds> -M <month> -y <year>

#  esxcli hardware clock set -d 11 -H 15 -m 28 -s 30 -M 01 -y 2019

The above example would set the hardware time and date to 2019-01-11T15:28:30
 

To set the time from vSphere Client:

1. Launch vSphere Client.
2. Go to Configuration > Time Configuration > Properties.
3. Input the correct Time and Date.
4. Click Options.
5. Click Restart on the Service Commands box.

To set the time from the vSphere Web Client:

1. Log into the vSphere Web Client. The default URL is https://vCenter_Server_FQDN:9443/vsphere-client
2. Go to Hosts and Clusters, from the Home screen >
3. Select the ESXi host > click the Manage tab > click the Settings button > under System, click Time Configuration
4. Click Edit > select Manually configure the date and time on this host radio button> Input the correct Time and Date
5. Click OK

 

Time Synchronization on the VMware Virtual Center Server and Windows 2003 Domain

To configure Microsoft Windows 2003 to use NTP time server, see the Microsoft Knowledge Base article 816042.

 

Note:The preceding link was correct as of January 30, 2014. If you find the link is broken, provide feedback and a VMware employee will update the link.

Additional Information

For translated versions of this article, see:

• 日本語: ESX ホストの環境全体の時刻同期の確認 (1033653)

Guide to configure NTP on ESX servers
ESX/ESXi ホスト環境における時刻同期の確認
Installing and Configuring NTP on an ESX host
Adjusting ESX host Time Zone
Configuring Network Time Protocol (NTP) on ESX/ESXi hosts using the vSphere Client
验证 ESX/ESXi 主机环境中的时间同步