How to troubleshoot Virtual machine(s) invalid in vCenter

Introduction

If you’ve ever encountered a virtual machine (VM) in vCenter that appears as “Invalid”, you know how frustrating it can be. An invalid VM is essentially unmanageable through the vSphere Client—it won’t power on, migrate, or function normally. This can be alarming, especially if the VM hosts critical workloads.

Why Does This Happen?

A VM might be marked as invalid due to several underlying issues, including:

• Loss of connection between vCenter and the ESXi host
• Corrupt or missing VM configuration files (.vmx, .vmdk, etc.)
• Storage issues, such as an inaccessible datastore
• Permissions or authentication problems preventing vCenter from reading the VM’s metadata
• Host disconnections or failures

What This Guide Covers

In this guide, we’ll walk through step-by-step troubleshooting techniques to diagnose and resolve an invalid VM state, including:

• Checking logs and diagnosing the issue
• Reloading or re-registering the VM
• Fixing storage-related problems
• Resolving corruption in VM configuration files
• Restarting services if needed

By following these steps, you’ll be able to restore your virtual machine to a functional state and prevent future occurrences. Let’s dive in.

Table of Contents

1. Introduction
2. Understanding the “Invalid” VM State
3. Initial Diagnosis
4. Step-by-Step Fixes
5. Preventing Future Issues
6. Conclusion

Understanding the “Invalid” VM State

Before jumping into troubleshooting, it’s important to understand what it means when a virtual machine is marked as “Invalid” in vCenter. This status indicates that vCenter is unable to retrieve the VM’s configuration or metadata, making it unmanageable from the vSphere interface.

Common Causes of an “Invalid” VM

Several factors can cause a VM to appear as invalid:

1. vCenter and ESXi Host Communication Issues
   • If vCenter loses connection to the ESXi host where the VM resides, it may mark the VM as invalid.
   • This can happen due to network disruptions, host failures, or vCenter service issues.
2. Corrupt or Missing VM Configuration Files
   • A VM’s metadata, including its .vmx and .vmdk files, may become corrupted or deleted.
   • If these files are missing or unreadable, vCenter won’t be able to register the VM properly.
3. Datastore Inaccessibility or Storage Failures
   • If the datastore hosting the VM becomes unavailable, disconnected, or corrupted, the VM may not be recognized.
   • Running out of storage space or a failed storage mount can also trigger this issue.
4. Permissions or Authentication Issues
   • vCenter or ESXi may lack sufficient permissions to access the VM’s files, causing it to appear invalid.
   • This can occur due to changes in user roles, group policies, or vSphere permissions.
5. Host Disconnections or Failures
   • If the ESXi host running the VM goes offline, crashes, or enters maintenance mode, vCenter may temporarily mark the VM as invalid.
   • If the issue persists after the host recovers, manual intervention may be needed.

Understanding these potential causes will help guide the troubleshooting process. In the next section, we’ll go over the initial steps to diagnose the problem and determine the best course of action.

Initial Diagnosis

Before attempting to fix an invalid virtual machine in vCenter, it’s crucial to diagnose the root cause. This section outlines the key steps to gather information about the issue and determine the best resolution path.

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Step 1: Check the vCenter Event Logs

vCenter logs contain valuable information that can help identify why a VM is marked as invalid.

How to Check Logs in the vSphere Client:

1. Navigate to vCenter > VMs and Templates.
2. Select the invalid VM (if still visible in the inventory).
3. Click on the Monitor tab > Events.
4. Look for any recent errors related to the VM, storage, or ESXi host.

If the VM isn’t listed in vSphere, check the vCenter service logs directly on the vCenter Server Appliance (VCSA):

bashCopyEditcat /var/log/vmware/vpxd.log | grep <VM_Name>

Look for error messages like “VM not found”, “Unable to access datastore”, or “Corrupt configuration”.

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Step 2: Verify Host and Datastore Connectivity

Since an invalid VM is often linked to storage or network issues, checking host and datastore connectivity is essential.

Check if the ESXi Host is Online

1. Go to Hosts and Clusters in the vSphere Client.
2. Ensure the ESXi host is connected and not in a disconnected or not responding state.
3. If the host appears disconnected, try reconnecting it:
   • Right-click the host and select Reconnect.
   • If that fails, restart the vCenter services (covered later in this guide).

Check Datastore Availability

1. Navigate to vCenter > Datastores.
2. Look for any datastores marked as inaccessible or unmounted.
3. Run the following command from the ESXi host to check available datastores:bashCopyEditesxcli storage filesystem list
4. If the datastore is missing, verify storage connections and remount if necessary.

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Step 3: Identify VM Power State

If the VM still appears in the ESXi inventory but is marked as invalid, try checking its power state.

1. SSH into the ESXi host where the VM was last running:bashCopyEditssh root@<ESXi_host_IP>
2. List all registered VMs:bashCopyEditvim-cmd vmsvc/getallvms
   • If the VM is not listed, it may have been removed from inventory or unregistered.
   • If the VM is listed but has an incorrect path, its storage location may have changed.
3. Attempt to reload the VM:bashCopyEditvim-cmd vmsvc/reload <VM_ID> If the reload succeeds, refresh the vSphere Client and check if the VM status updates.

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Step 4: Verify VM Configuration Files

If the VM’s .vmx file is missing or corrupted, vCenter cannot recognize it properly.

1. Navigate to the VM’s expected directory:bashCopyEditcd /vmfs/volumes/<datastore>/<VM_Name>
2. List the contents:bashCopyEditls -l
   • Ensure that the .vmx file exists.
   • If the .vmx file is missing or corrupted, it may need to be rebuilt (covered in the next section).

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Step 5: Review vCenter and ESXi Services

If the issue appears widespread (multiple VMs are invalid), it could be a vCenter or ESXi service problem. Restarting relevant services might resolve it.

Restart vCenter Services (VCSA Only)

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

Restart ESXi Management Services

bashCopyEdit/etc/init.d/hostd restart
/etc/init.d/vpxa restart

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Next Steps

Once you’ve diagnosed the cause of the invalid VM, the next section will guide you through specific fixes based on the issue type, including reloading the VM, re-registering it, fixing storage issues, and recovering from corrupt files.

Also See: Configuring Kernel Virtual Machines!

Step-by-Step Fixes

Now that you’ve diagnosed the cause of the “Invalid” VM state, it’s time to apply the appropriate fix. Below are several methods to recover the VM based on the issue type.

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Option 1: Reload the VM in vCenter

If the VM appears in the ESXi inventory but is invalid, try reloading it to force vCenter to recognize it again.

Steps:

1. SSH into the ESXi host where the VM resides:bashCopyEditssh root@<ESXi_host_IP>
2. List all registered VMs:bashCopyEditvim-cmd vmsvc/getallvms
   • Find the VM ID from the output.
3. Reload the VM:bashCopyEditvim-cmd vmsvc/reload <VM_ID>
4. Refresh the vSphere Web Client and check if the VM state updates.

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Option 2: Remove and Re-Register the VM

If reloading does not work, removing and re-adding the VM to the inventory may resolve the issue.

Steps:

1. In the vSphere Web Client, locate the invalid VM.
2. Right-click the VM and select Remove from Inventory (do NOT delete the files).
3. Browse the datastore where the VM is stored:
   • Navigate to Datastore Browser > Locate the VM folder.
4. Find the .vmx file.
5. Right-click it and select Register VM.
6. Once registered, try powering on the VM.

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Option 3: Reconnect the ESXi Host

If multiple VMs are showing as invalid, the issue may be with the ESXi host.

Steps:

1. Open vSphere Web Client and navigate to Hosts and Clusters.
2. Right-click the ESXi host and select Disconnect.
3. Wait for 30 seconds, then right-click the host again and select Reconnect.
4. If the issue persists, restart management services on the host:bashCopyEdit/etc/init.d/hostd restart /etc/init.d/vpxa restart

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Option 4: Fix Datastore and Storage Issues

If the VM’s storage is inaccessible, vCenter cannot read the VMX file.

Steps:

1. Check if the datastore is mounted:bashCopyEditesxcli storage filesystem list
2. If missing, try remounting it:bashCopyEditesxcli storage filesystem mount -u <UUID>
3. If the datastore is unavailable due to NFS/iSCSI issues, restart the storage service:bashCopyEdit/etc/init.d/lwiod restart /etc/init.d/nfs restart

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Option 5: Repair a Corrupt VMX File

If the VM’s configuration file is corrupt or missing, vCenter cannot register it.

Steps:

1. Navigate to the VM’s directory:bashCopyEditcd /vmfs/volumes/<datastore>/<VM_Name>
2. Check if the .vmx file is present:bashCopyEditls -l *.vmx
3. If the file is missing, restore from a backup or create a new one:bashCopyEditcp <backup>.vmx <VM_Name>.vmx
4. Re-register the VM:bashCopyEditvim-cmd solo/registervm /vmfs/volumes/<datastore>/<VM_Name>/<VM_Name>.vmx

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Option 6: Restart vCenter Services

If multiple VMs are affected or none of the above fixes work, restart vCenter services.

Steps for vCenter Server Appliance (VCSA):

1. SSH into the vCenter Server:bashCopyEditssh root@<vCenter_IP>
2. Restart all services:bashCopyEditservice-control --stop --all service-control --start --all

Steps for Windows-based vCenter:

1. Open Services.msc.
2. Restart VMware vCenter Server.

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Next Steps

Once the VM is restored, the final section will focus on preventing this issue in the future, including monitoring strategies, backup recommendations, and best practices.

Preventing Future Issues

Now that you’ve successfully resolved the “Invalid” VM issue, it’s important to take steps to prevent it from happening again. Below are key best practices for maintaining vSphere stability and avoiding VM inconsistencies.

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1. Monitor vCenter and ESXi Logs Regularly

vCenter and ESXi logs can provide early warnings before issues escalate. Set up proactive log monitoring using:

• vRealize Log Insight or Splunk for log aggregation.
• Regular checks of logs via SSH:bashCopyEdittail -f /var/log/vmware/hostd.log tail -f /var/log/vmware/vpxd.log
• Alerts for critical events (e.g., lost storage connections, corrupted VMX files).

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2. Ensure Datastores Are Redundant and Monitored

Many invalid VM issues stem from storage failures or inaccessibility. To mitigate this:

• Use multipath storage configurations to prevent single points of failure.
• Regularly check datastore health in vCenter:
  • Navigate to Datastores > Monitor > Performance.
• Implement storage redundancy (vSAN, RAID, or storage replication).
• Set up alerts for low disk space or datastore disconnections.

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3. Automate Backups of VM Configuration Files

Since VMX corruption can make a VM unmanageable, create regular backups of VM metadata:

1. Manually backup VMX files:bashCopyEditcp /vmfs/volumes/<datastore>/<VM_Name>.vmx /vmfs/volumes/backup/
2. Use VMware snapshots carefully (excessive snapshots slow performance).
3. Implement full VM backups using:
   • VMware Veeam Backup & Replication
   • vSphere Data Protection (VDP)
   • Rubrik or Cohesity for enterprise backup solutions

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4. Keep vCenter and ESXi Updated

VMware frequently releases patches for bug fixes, storage stability, and VM management improvements.

• Check for updates regularly:
  • In vSphere, go to Lifecycle Manager > Updates.
  • Run the following command on ESXi:bashCopyEditesxcli software profile update -d <update_bundle>
• Maintain a test environment for updates before deploying them in production.

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5. Implement Proper VM and Host Management Practices

• Avoid force power-offs of VMs unless absolutely necessary.
• Prevent unauthorized modifications to VMX and VMDK files by restricting access via vSphere Role-Based Access Control (RBAC).
• When moving or migrating VMs, use Storage vMotion instead of manual file copies.

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By following these best practices, you can reduce the likelihood of encountering “Invalid” VMs in vCenter. Keeping your hosts, storage, and vCenter infrastructure stable will ensure smooth VM operations and minimal downtime.

In the next section, we’ll summarize the key troubleshooting steps and provide additional resources for further machine learning.

Conclusion

Troubleshooting an “Invalid” virtual machine in vCenter can be challenging, but by following a systematic approach, you can quickly identify and resolve the issue. This guide covered:

Key Takeaways

✅ Understanding the Invalid VM State – Knowing why a VM appears invalid helps narrow down the cause (storage issues, configuration corruption, or host disconnection).

✅ Diagnosing the Problem – Checking vCenter logs, verifying datastore accessibility, and confirming ESXi host status provide valuable insights.

✅ Applying Fixes – Solutions like reloading the VM, re-registering it, fixing datastore issues, and repairing corrupted VMX files often restore the VM.

✅ Preventing Future Issues – Implementing monitoring, redundancy, backups, and regular updates significantly reduces the risk of invalid VMs appearing again.

Next Steps

• If the issue persists, consider contacting VMware Support with log files for deeper analysis.
• Bookmark this guide as a reference for future troubleshooting.
• Implement preventative best practices to minimize downtime and maintain a stable vSphere environment.

For further learning, check out VMware’s official documentation:
🔗 VMware Knowledge Base (KB)
🔗 VMware vSphere Documentation

If you found this guide helpful, share it with your team and stay proactive in maintaining your virtual infrastructure!