Cloning a virtual machine is really simple. In the case of KVM it is as simple as turning off the source virtual machine for data consistency and using the virt-clone command.

It can be done in two ways, following a wizard by running virt-clone with the -prompt parameter or bypassing all necessary parameters.

In the first case simply answer the questions that are emerging, which basically are:

  1. Name of the source virtual machine to be cloned.
  2. Name for the resulting virtual machine.
  3. Path to disk or cloned disks (destination disks).

With this example we show step by step how to clone the machine name_of_new_vm and create the machine name_of_current_vm:

1 Suspend the source virtual machine

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virsh suspend name_of_current_vm

2 Run the virt-clone command

  • Prompt option:
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    # virt-clone --prompt
What is the name of the original virtual machine?
name_of_current_vm
What is the name for the cloned virtual machine?
name_of_new_vm
What would you like to use as the cloned disk (file path) for '/data2/KVM/name_of_current_vm_d1.raw'?
/data2/KVM/name_of_new_vm_d1.raw
Cloning name_of_new_vm_d1.raw                                                                                                                                                                                             |  36 GB     01:14

Clone 'name_of_current_vm' created successfully.
  • Command line option:
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    # virt-clone -o name_of_current_vm -n name_of_new_vm -f /data2/KVM/name_of_new_vm_d1.raw

2.1 Multiple disks

If the original machine has multiple disks, you must use the -f ( -file ) parameter as many times as you have defined in XML of the server in the corresponding order. For example:

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virt-clone -o master_server -n srvdb_master -f /dataocz/KVM/srvdb_master_d1.raw -f /dataocz/KVM/srvdb_master_d2.raw

3 Start the new virtual machine

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# virsh start name_of_new_vm
Domain name_of_new_vm started

4 Determine on which port you are listening to the new machine

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# virsh vncdisplay name_of_new_vm
:2

Booting the VNC Viewer (View link) to finish configuring the new machine (Hostname, IP Address, etc.).

5 Resume source virtual machine

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# virsh resume name_of_current_vm
Domain name_of_current_vm resumed