How to clone a virtual machine in VMware ESXi with or without vCenter

Cloning a virtual machine in VMware ESXi might seem like a complex task, but it's a fundamental skill today if you manage any type of virtual infrastructure. Whether you want to run tests without affecting your production environment, perform a migration, or simply save time creating repetitive environments, knowing all the available options will allow you to choose the most effective one based on your resources and configuration.

In this article, I'll explain how to clone virtual machines in VMware ESXi , whether you have access to vCenter or are working with standalone hosts. You'll also learn about advanced alternatives using external tools like Vinchin and NAKIVO, which simplify this task and offer additional advantages such as automated replication and disaster recovery.

What exactly is cloning a VM?

Cloning a virtual machine involves creating an exact replica of an existing VM . This means generating a complete copy of the virtual hardware , operating system, network configurations, hard drives, and other settings. This technique allows you to deploy functionally identical machines in a matter of minutes, making it ideal for testing environments, mass deployments, or service migrations . For more information on managing these tasks, you can consult the article on how to copy a VMware virtual machine to another PC.

This differs from a snapshot, which captures the state of a VM at a specific point in time but cannot be run separately . A snapshot is useful for recovery, but not for duplicating executable machines.

Classic Method: Clone a VM with vCenter Server

The simplest and most direct way to clone a VM is by using vCenter Server . This tool provides a very intuitive graphical interface that automates almost the entire process.

To do this, you just need to open the vSphere Web Client connected to your vCenter instance and follow these steps:

1. Access the section Hosts and Clusters and locate the VM you want to clone.
2. Right click on the VM and select Clone > Clone to Virtual Machine.
3. Give the cloned machine a new name and choose the destination folder from the inventory.
4. Select the physical host or cluster where the clone will be executed.
5. Specifies the data warehouse where the files of the new VM will be saved.
6. Define the disk configuration (thin or thick provisioning) and whether you want it to start automatically after cloning.
7. Review the options summary and confirm the transaction.

Once the cloning process is complete, you'll have a new VM registered and ready to use. This procedure is extremely reliable and fast, but it requires a vCenter license , which may not be affordable for everyone. If you're looking for more economical options, it's also worth considering hard drive cloning software.

Clone a VM without vCenter with VMware Host Client

If you don't have vCenter, you can still clone virtual machines using the native web interface of each ESXi host , known as VMware Host Client. Although the process is manual, it is entirely feasible and effective.

This method involves copying the .vmx and .vmdk files from the original VM to a new directory, modifying the identifiers, and manually registering the new machine on the host.

The general steps are as follows:

1. Shut down the original VM that you want to clone.
2. Access the Host Client and create a new directory within the datastore where you will save the copy.
3. Use the data warehouse browser to copy the .vmdk and .vmx files to the new directory.
4. Download the file .vmx, open it in a text editor and change the VM name and disk references if necessary.
5. Upload the modified .vmx to the new directory again.
6. Register the new VM from the option Create/Register virtual machine selecting the option to use an existing VM.
7. After registration, you will be able to start the clone and the system will ask you if it has been copied or moved. Select “Copied.”

This process may seem more technical, but it gives you complete control over cloning and is entirely viable in environments without additional licenses. Even so, you need to be careful of MAC, UUID, and SID conflicts if working with Windows machines integrated into domains.

Another manual alternative: create a new VM and insert the existing disks

There is a third, very interesting way if you don't want to touch configuration files, which is to manually create a new VM and connect the disks of an existing one.

Here the process is:

1. Shut down the original VM.
2. Create a new VM from scratch, but without adding a hard drive during setup.
3. From the data warehouse browser, copy the file .vmdk of the original VM to the new directory of the cloned VM.
4. Edit the settings of the new VM and add existing hard drive pointing to the copied path.
5. Save the changes and start the new VM.

This method avoids modifying the .vmx file , making it safer for users who are uncomfortable altering configuration files. It will work as long as the base configuration of both machines is the same (CPU, RAM, hardware compatibility, etc.).

Cloning from the command line on ESXi

You can also clone VMs directly using commands from the ESXi shell or by connecting via SSH . This method is ideal if you are comfortable using the terminal and have root access to the system.

The general steps are:

1. 1. Connect via SSH or access the ESXi shell.
   2. Usa vim-cmd vmsvc/getallvms to list the registered VMs and note the VMID of the machine you want to clone.
   3. Shut down the VM using vim-cmd vmsvc/power.off [VMID].
   4. Create a new destination directory with mkdir.
   5. Usa vmkfstools -i To clone the virtual disks to the new directory:

vmkfstools -i /origen/Windows-VM.vmdk /destino/Win-VM-Clone2.vmdk -d thin

1. 1. Copy the .vmx file with cp and edit its content with vi To update names:

:%s/Windows-VM/Win-VM-Clone2/g

1. Register it with vim-cmd solo/registervm /ruta/Win-VM-Clone2.vmx.
2. Power on the cloned VM: vim-cmd vmsvc/power.on [nuevo VMID].

This process, while technical, offers maximum flexibility and is ideal when working across multiple hosts or automating deployments via scripts. If you're interested in learning more about how to do this in conjunction with other tasks, check out the article on hard drive repair software.

Using external tools: cloning with NAKIVO Backup & Replication

If you manage many VMs or your infrastructure requires repetitive or automated processes, one of the most recommended options is to use external tools such as NAKIVO Backup & Replication.

NAKIVO allows you to clone virtual machines using the replication feature and offers advantages such as:

• Clone VMs from one host to another even if they are not in the same vCenter.
• Schedule periodic replications.
• Keep multiple restore points.
• Space reduction thanks to deduplication and compression.

The process consists of:

1. Add ESXi hosts or vCenter to NAKIVO.
2. Create a new replication job from the console.
3. Select the original VM, destination, network and re-IP options, and schedule the task.
4. Run the job and monitor it from the main panel.

Once completed, you will have a functional virtual machine at your chosen destination, without needing to manually touch files or worry about conflicts.

Vinchin Backup & Recovery as a more economical alternative

Another perfectly valid option is Vinchin Backup & Recovery , a backup solution that allows you to restore VMs on other hosts as if they were clones.

This software offers:

• A very intuitive web console.
• Cloned from backups, no vCenter required.
• Premium features like CBT, deduplication and compression.

The flow would be:

1. Configure a backup job on the original VM.
2. Select a destination repository to store the data.
3. Run the job.
4. From the “Recovery” option, select the new host and restore the VM with a different name.

The advantage is that in addition to achieving effective cloning, you will also be protecting your data as part of the process.

Frequently Asked Questions When Cloning VMs in VMware

Can you clone a VM while it is running?
Yes, although it's not recommended in all cases. Some tools like vCenter or NAKIVO allow you to do this, but it's safest to turn it off first to avoid inconsistencies.

What about the hostname, MAC and SID?
When cloning a machine, you must be careful to change these unique identifiers, especially in Windows environments. To do this, you can use Sysprep or rename manually from the operating system.

Can I clone an entire ESXi host?
Not as such. ESXi doesn't have a host-level clone feature, but you can replicate the configuration and restore VMs to another host.

What is the best option for large environments?
For infrastructures with many VMs or strict availability requirements, it's ideal to opt for solutions like NAKIVO or Vinchin, which automate and easily scale cloning, backup, and recovery operations.

Cloning virtual machines in VMware can take multiple paths depending on your context, expertise, and available tools. From graphical interfaces to terminals and complete commercial solutions, there's always an option to suit your needs. The key is to identify which one offers the right balance of time, control, and scalability for your virtualized environment.