Practical Method for Resetting vCenter Password – Safe Recovery Without Reinstall

 Introduction

Recently, while upgrading a customer's vCenter, I encountered a situation where the root password was unknown. The customer also asked around but couldn't find it. To recover this root password, I did some research, and today I'm sharing it here. The practical environment for this operation: VMware vSphere vCenter 8.0.

Steps:

1. Use the Administrator@vsphere.local account to log in to https://vCenterIP:5480.

2. Navigate to the "Access" tab and check whether vCenter SSH login is enabled. If SSH remote access is not activated, click "Edit" and enable "Activate SSH Login."

3. Use the Administrator@vsphere.local account to SSH remotely into the vCenter server.

4. Type "shell.set --enabled true" to enable the shell function.

 
shell.set--enabled true

5. Type "shell" to enter the shell bash interface.

6. Use "sudo passwd root" to update the root password. Enter the new password twice.

7. Sometimes the account might be locked, so we need to unlock it first.

version before 8.0 u2 

 
sudo pam_tally2 --user=root --reset

version after 8.0 u2 (include 8.0 u2)

 
sudo /usr/sbin/faillock --user root --reset

Your Can Refer to this VMware official document:

• VMware Official vCenter Password Recovery Documentation
  https://docs.vmware.com/en/VMware-vSphere/index.html

• VMware vCSA Security & Access Management
  https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security

🔍 Why vCenter Password Reset Is a Common Admin Challenge

Password-related lockouts are one of the most frequent vCenter operational issues, especially in environments with:

• Password expiration policies

• Staff turnover

• MFA misconfiguration

• Limited documentation

Using a practical and supported vCenter password reset method helps administrators restore access without risking data loss or reinstallation.

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🛠 Common Scenarios That Require Resetting vCenter Passwords

You may need to reset a vCenter password when:

• The root or administrator password is forgotten

• vCenter services are running, but the login fails

• Password expired, and SSH access is blocked

• Appliance shell is disabled

• Access is needed urgently during outages

This practical reset approach minimizes downtime and avoids unnecessary rebuilds.

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✅ Best Practices Before Resetting vCenter Passwords

Before performing a password reset, always:

• Take a snapshot of the vCenter appliance

• Ensure console access via ESXi or vSphere

• Confirm the exact vCenter version

• Schedule a maintenance window if possible

These steps reduce the risk of recovery and help ensure a smooth reset process.

🔹 Password & Recovery Related

• vCenter 8.0 Password Recovery from GRUB
  https://anfuitblog.blogspot.com/2025/12/vcenter-80-password-recovery-from-grub.html

• How to Reset VMware vCenter 6.7 Root Password
  https://anfuitblog.blogspot.com/2025/09/how-to-reset-vmware-vcenter-67-root.html

🔹 Service & Access Troubleshooting

• VMware vCenter 503 Service Unavailable – Troubleshooting Guide
  https://anfuitblog.blogspot.com/2025/08/vmware-vcenter-503-service-unavailable.html

• Practical Method for Resetting vCenter Password

 VMware Troubleshooting Guide – Fix Common ESXi and vCenter Issues Step by Step

Introduction

Running virtualized environments with VMware provides powerful flexibility, but administrators often face challenges like storage problems, VM errors, and vCenter connection failures.

This VMware troubleshooting guide will walk you through common ESXi and vCenter issues and provide practical fixes to keep your infrastructure stable. Whether you are dealing with a datastore full error, snapshot problems, or VMware vCenter service outages, these solutions will help you maintain performance and reliability.

1. Fixing VMware ESXi Storage Issues

One of the most common VMware problems is the datastore full error. This typically happens when:

• Snapshots are left running too long

• Old ISO files take up space

• Log files grow uncontrollably

How to Fix

• Identify space usage:

   
  df -h
  du -sh /vmfs/volumes/*
  

• Delete unnecessary ISOs or logs.

• Consolidate or remove old snapshots from the vSphere Client.

👉 Related: VMware ESXi Cannot Expand VMFS

2. Resolving VMware Snapshot Errors

Snapshots are useful but can cause performance degradation or even prevent VM operations if misused.

Best Practices:

• Never keep snapshots longer than a few days.

• Always consolidate snapshots after backup jobs.

• Monitor snapshot size using PowerCLI:

   
  Get-VM | Get-Snapshot | Select VM, Name, SizeMB
  

3. Troubleshooting VMware vCenter “503 Service Unavailable” Error

The vCenter 503 error occurs when backend services fail to start or resources are exhausted.

Fix Steps

• Restart services:

   
  service-control --stop --all 
  service-control --start --all
  

• Check logs in /var/log/vmware/ for failed components.

• Ensure enough CPU, RAM, and disk space are allocated.

📖 See also: Fix VMware vCenter 503 Service Unavailable

4. Networking and vSwitch Problems in VMware ESXi

VMs may lose connectivity due to vSwitch misconfigurations or incorrect NIC mappings.

Quick Fix

• Verify port group assignment in vSphere Client.

• Check physical NIC status with:

   
  esxcli network nic list
  

  esxcli network nic list
  

• Use VMware KB and the Oracle Cloud Support Note for guidance on compatibility and configuration.

Conclusion

VMware environments are robust, but issues with storage, snapshots, networking, and vCenter services can disrupt operations. By following these VMware troubleshooting best practices, you can fix common errors quickly and maintain system stability.

The next time you face errors like “VMware ESXi datastore full” or “vCenter 503 Service Unavailable”, refer back to this guide for step-by-step solutions. A proactive approach with regular monitoring, snapshot management, and resource planning will help you prevent most issues before they impact your virtual infrastructure.