[Solved] How to Fix vCenter Cannot Synchronize Host Error

Have you ever met the error displays vCenter cannot synchronize host when connecting ESXi host to vCenter Server? This article will show you the steps to fix the issue.


By Crystal / Updated on January 31, 2023

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Error: VMware vCenter cannot synchronize host


Hello all, I just starting to use vCenter but find that almost all of our ESXi hosts have the error “Cannot synchronize to host”. I have tried to resolve this issue myself and doing my own research, but nothing i read gives me any ideas about where to start. Am i missing something glaringly obvious? I appreciate any and all help.

- Question from www.reddit.com

VMware vCenter Server is a centralized platform for administrators to manage vSphere environments more efficiently. However, when connecting ESXi hosts in vCenter, some people may find themselves fail to update the information to vCenter Server, and displayed with the errors such as

  • VMware ESXi cannot synchronize host “incorrect username and password”.
  • Cannot synchronize host: Cannot complete login due to an incorrect user name or password.

Error: Cannot synchronize host

This happens because the password of the vpxuser account, which is a proxy created by vCenter when adding an ESX/ESXi host, is out of sync with the vCenter Server database and the password on the host or the password is manually modified.

The resolution is simple. According to VMware’s Knowledge Base article, you just need to re-register the vpxuser account and resynchronize the password with the vCenter Server database. Next, this article will show you the steps.

How to fix error: vCenter cannot synchronize host

1. In vCenter, right-click the ESXi host and select Connection > Disconnect.

Disconnect host

2. Connect to ESXi host from web client and navigate to Local Users & Groups > Users tab. Right-click on vpxuser and select Remove.

Remove vpxuser

3. Connect to the Console of the ESXi host and press F2 to enter the System Customization, log in as root, select Troubleshooting Options and click Restart Management Agents.

Restart management agents

4. Back to vCenter, right-click on the host and select Connection > Connect, and provide the username and password to reconnect the host to vCenter Server.

Necessary data protection: Batch backup VMs managed by vCenter

You may already know that it is necessary to perform image-based backup of large amounts of VMs managed by vCenter Server, however, vCenter Server does not provide the feature of virtual machine backup. And that makes backup software a commonly accepted choice.

Here I introduce you to a VMware backup software AOMEI Cyber Backup, it enables you to backup multiple VMs either managed by vCenter Server, or on a standalone ESXi host.

Agentless Backup: create complete and independent image-level backup for VMware ESXi and Hyper-V VMs.
Flexible vSphere Backup: batch backup large numbers of VMs managed by vCenter Server, or multiple VMs on a standalone ESXi host.
Multiple Storage Destinations: backup to local drive, or network destinations like NAS.
Automated Execution: create backup schedules to automate backups daily, weekly, monthly.
Restore Entire VM: restore instant available VMs from any selected restore points to an original or new location.

AOMEI Cyber Backup supports both paid and free versions of VMware ESXi 6.0 and later versions. Next, I will show you how to batch backup VMs managed by vCenter Server with AOMEI Cyber Backup in 4 simple steps.

You can click the following button to download the 30-day free trial.

Download Free trialVMware ESXi & Hyper-V
Secure Download

*You can choose to install this VM backup software on either Windows or Linux system.

4 Steps to batch backup VMs managed by vCenter Server

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.

Add VMware ESXi host

2. Create Backup Task: Navigate to Backup Task > + Create New Task, and select VMware ESXi Backup as the Backup Type.

3. Set the Task Name, Device, Target, Schedule and Cleanup as needed.

  • Task Name: you can change the task name or use the default name with an ordinal.
  • Device: batch select large numbers of VMs managed by vCenter Server for centralized backup.

Select virtual machines vCenter

  • Target: select to back up to a local path, or to a network path like NAS.
  • Schedule (optional): perform full, differential, or incremental backup, and automate execution according to the frequency you specified.
  • Cleanup (optional): automatically delete the old backup copies that exceed the retention period you specified.

4. Run Backup: Now you can click Start Backup and select Add the schedule and start backup now, or Add the schedule only.

Start Backup

Created backup tasks will be listed and monitored separately for restoring, progress checking and schedule changing.

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.


Vpxuser is a proxy account with full administrative privileges that created by vCenter when adding a ESXi host. However, if you manually modified the vpxuser password which makes it out of sync with vCenter database, it may cause VMware cannot synchronize host. Thus, VMware does not recommend to modify the vpxuser account. This article showed the steps on how to fix the vCenter cannot synchronize host error.

If you are concerned that errors may lead to unexpected data loss, performing regular backups is an effective way to save you from this situation. You can try AOMEI Cyber Backup which allows you to batch backup VMware ESXi VMs managed by vCenter.

Crystal · Editor
Crystal is an editor from AOMEI Technology. She mainly writes articles about virtual machine. She is a positive young lady likes to share articles with peolpe. Off work she loves travelling and cooking which is wonderful for life.