VMware ESXi and vSphere Cluster Management

Configure a VMware Workstation Player Virtual Machine to Keep the Same UUID

Learn how to keep a VMware Workstation Player VM's UUID when moving it, edit uuid.action in the VMX file, validate the result, and avoid duplicate identity conflicts.

Overview

VMware Workstation Player can ask whether a virtual machine was moved or copied when it is opened from a different location. That choice can affect the VM's identity. If you are relocating one VM and want management tools to continue recognizing it as the same machine, configure the VMX file to keep its existing UUID.

This procedure applies to VMware Workstation Player virtual machines that use a text-based .vmx configuration file.

What the Virtual Machine UUID Means

UUID stands for Universally Unique Identifier. A virtual machine UUID is a VMware-level value associated with a particular VM. It helps distinguish that VM from other VMs in inventory, automation, management, licensing, monitoring, and backup systems.

The VM UUID is not the same as the following values:

• Guest operating system identifier: an ID generated inside Windows, Linux, or another guest operating system.
• Virtual disk identifier: a value associated with a virtual disk file or its presentation to the guest.
• MAC address: the hardware address assigned to a virtual network adapter.
• Application-specific ID: an identifier created by software installed inside the guest, such as a license or installation ID.
• Hostname or IP address: network and operating system settings that can change independently of the VMware UUID.

Keeping the UUID can matter when an inventory system, license server, monitoring platform, backup tool, or automation workflow uses the VMware-level identity to recognize a VM.

Moved Versus Copied Virtual Machines

A moved virtual machine is relocated to another directory, drive, computer, or storage location without intending to create an independent second VM. A copied virtual machine is a separately usable duplicate, usually expected to receive its own identity.

When VMware detects that a VM is being opened from a different location, it may display a moved-or-copied decision prompt. Selecting copied can cause VMware to generate new identifying values. Selecting moved is appropriate when the original VM is no longer being used in its original location and you want to retain its identity.

Before Editing the VMX File

1. Shut down the guest operating system normally.
2. Confirm that the VM is powered off, not suspended, paused, or merely closed.
3. Close VMware Workstation Player, or at minimum ensure that the VM is not running and its files are not being modified.
4. Locate the folder containing the VM files. The configuration file normally has the VM's name and ends in .vmx.
5. Make a backup copy of the .vmx file. This gives you a way to restore the previous configuration if a manual edit causes a problem.

Configure VMware to Keep the UUID

1. Open the VM's .vmx file in a plain-text editor. Do not use a word processor that adds formatting.
2. Add this configuration entry, commonly at the end of the file:

uuid.action = "keep"

1. Save the file as plain text, preserving the original .vmx filename and extension.
2. Reopen VMware Workstation Player if you closed it.
3. Open or start the VM.

The uuid.action property controls VMware's response when the VM appears to have been moved or copied. The keep value instructs VMware to retain the existing VM UUID and suppresses the moved-or-copied identity decision in the situations covered by the setting.

Validate the Configuration

After saving the file, use this checklist:

• Close and reopen VMware Workstation Player.
• Confirm that the VM starts without the expected moved-or-copied prompt.
• Reopen the .vmx file and verify that the exact entry uuid.action = "keep" is still present.
• If identity preservation is important, record the VM UUID before moving the VM and compare it after the move using the VMware interface or the VM's configuration and inspection tools.
• Check that you edited the VMX file belonging to the VM you actually opened, rather than a backup, stale copy, or similarly named VM.

For example, when transferring a development VM to another workstation, power it off, back up and edit its VMX file, transfer the complete VM folder, and then start the relocated VM. The setting helps tools that use the VMware UUID continue to identify it as the same VM.

Identifiers That May or May Not Be Preserved

Risks of Duplicate UUIDs

Keeping a UUID is best suited to moving a VM, not to operating independent clones. If the original and copied VM are both accessible and active with the same UUID, inventory systems may treat them as one machine. This can produce conflicts in licensing, monitoring, backup selection, automation, and other management systems.

For an independent lab clone, allow VMware to generate a new identity. Also review the clone's hostname, network configuration, guest operating system ID, MAC address, and application licensing state as appropriate.

Troubleshooting

The moved-or-copied prompt still appears

• Power off the VM completely; editing while it was suspended or running may not work.
• Confirm that you edited the active VM's VMX file in the correct folder.
• Verify the exact syntax: uuid.action = "keep".
• Make sure the file was saved and that the editor did not add a second extension such as .txt.
• Close and restart VMware Workstation Player, then test the VM again.
• Consider whether your VMware edition or version handles this setting differently or overrides it.

Software inside the guest still reports a different identity

The software may not use the VMware UUID. Identify whether it relies on a guest machine ID, hostname, MAC address, disk serial number, or application-specific identifier. Manage that value separately and follow the software vendor's rules for moving or cloning installations.

Two VMs conflict after a copy

The original and copied VMs may be retaining the same UUID while being used as separate machines. Remove UUID retention from the independent copy or restore its original configuration, then allow VMware to assign a new identity. Review duplicated guest and network settings as well.

The VMX file cannot be edited

• Shut down the VM and close programs that may have its files open.
• Check filesystem permissions and use an account with permission to modify the VM folder.
• If the VM is in a protected or synchronized directory, move it to a writable location or adjust the directory configuration.
• Keep the backup made before editing so you can recover the original VMX file.

Scope and Limitations

This procedure is specific to VMware Workstation Player and VMX-based virtual machines. Configuration behavior can vary by VMware product edition and version. A setting may be overridden, unavailable, or handled differently in another VMware product.

Use UUID retention when one VM is being relocated and its existing identity must remain stable. Use normal copy or clone identity-generation behavior when creating a separate VM that will operate concurrently with the source.

For related work, see this guide to keeping a VMware virtual machine UUID.