Virtual Machine Cloning

Virtual machine cloning refers to creating a copy of a virtual machine at its current point in time. The cloned virtual machine contains all configurations, operating systems, applications, and data of the original virtual machine.

Prerequisites

• To use the virtual machine cloning feature, its disk must use a storage class that supports snapshot functionality. Virtual machine snapshots save the current state of the virtual machine and can be used to restore the virtual machine to this point in time in case of unexpected failures.

• Install the jq package on the node where the script needs to be executed. jq is a lightweight command-line JSON processing tool used for parsing and processing JSON data.

Procedure

Note: All the operations below must be performed on the master node of the cluster where the virtual machine is located.

1. Open the CLI tool.

2. Execute the following command to create and open the vm-clone.sh file.

   vi vm-clone.sh

3. Type i and copy the following content into the vm-clone.sh file.

   #!/bin/bash
   
   vm_clone() {
     NAMESPACE=$1
     VM_NAME=$2
     VM_CLONE_NAME=$3
   
     cat <<EOF | kubectl create -f -
   kind: VirtualMachineClone
   apiVersion: clone.kubevirt.io/v1alpha1
   metadata:
     name: clone-$VM_NAME
     namespace: $NAMESPACE
   spec:
     source:
       apiGroup: kubevirt.io
       kind: VirtualMachine
       name: $VM_NAME
     target:
       apiGroup: kubevirt.io
       kind: VirtualMachine
       name: $VM_CLONE_NAME
     labelFilters:
       - "*"
       - "!ovn.kubernetes.io/*"
     annotationFilters:
       - "*"
       - "!ovn.kubernetes.io/*"
     template:
       labelFilters:
         - "*"
         - "!ovn.kubernetes.io/*"
       annotationFilters:
         - "*"
         - "!ovn.kubernetes.io/*"
   EOF
   
     if [ $? -eq 0 ]; then
       echo "Create vmclone resource Succeeded"
     else
       echo "Create vmclone resource failed"
       exit 1
     fi
   
     echo "Waiting for vm clone completion"
     while true; do
       phase=$(kubectl -n $NAMESPACE get vmclone clone-$VM_NAME -o jsonpath='{.status.phase}')
       if [ "$phase" == "Succeeded" ]; then
         break
       elif [ "$phase" == "Failed" ]; then
         echo "VirtualMachineClone resource phase is Failed"
         exit 1
       fi
       sleep 5
     done
     echo "vm clone completion"
   
     dvList=$(kubectl -n $NAMESPACE get vm $VM_CLONE_NAME -o jsonpath='{.spec.template.spec.volumes}' | jq . | grep restore- | grep name | awk '{print $2}')
   
     for dv in $dvList; do
       kubectl -n $NAMESPACE label --overwrite dv $(echo $dv | sed 's/\"//g') vm.cpaas.io/used-by=$VM_CLONE_NAME
       if [ $? -ne 0 ]; then
         echo "update DV label failed"
         exit 1
       fi
     done
   
     pvcList=$(kubectl -n $NAMESPACE get vm $VM_CLONE_NAME -o jsonpath='{.spec.template.spec.volumes}' | jq . | grep restore- | grep claimName | awk '{print $2}')
   
     for pvc in $pvcList; do
       kubectl -n $NAMESPACE label --overwrite pvc $(echo $pvc | sed 's/\"//g') vm.cpaas.io/used-by=$VM_CLONE_NAME
       if [ $? -ne 0 ]; then
         echo "update PVC label failed"
         exit 1
       fi
     done
   }
   
   if [ $# -ne 3 ]; then
     echo "error: parameters error"
     echo "Usage: ./vm-clone.sh NAMESPACE VM_NAME VM_CLONE_NAME"
     exit 1
   fi
   
   # exec vm clone
   vm_clone "$1" "$2" "$3"

4. Type shift+:wq to save the file.

5. Execute the following command to add execution permissions to the vm-clone.sh file.

   chmod +x vm-clone.sh

6. Execute the following command to run the script file.

   ./vm-clone.sh <NAMESPACE> <VM_NAME> <VM_CLONE_NAME>

   Parameter description:

   • NAMESPACE: Enter the namespace where the virtual machine to be cloned is located. Replace <NAMESPACE> with this namespace.
   • VM_NAME: Enter the name of the virtual machine to be cloned. Replace <VM_NAME> with this name.
   • VM_CLONE_NAME: Enter the name of the cloned virtual machine. Replace <VM_CLONE_NAME> with this name.

7. When you see output similar to the following, the cloning is complete.

   virtualmachineclone.clone.kubevirt.io/clone-k1 created
   Create vmclone resource Succeeded
   Waiting for vm clone completion
   vm clone completion
   datavolume.cdi.kubevirt.io/restore-e8ff0e7b-dc7e-4140-aec7-8556cfcf4533-rootfs labeled
   datavolume.cdi.kubevirt.io/restore-e8ff0e7b-dc7e-4140-aec7-8556cfcf4533-1 labeled

Related Operations

View and Start the Cloned Virtual Machine

1. In the left navigation bar, click Virtualization > Images.

2. You can see the cloned virtual machine with the name specified in the Run Script step. The cloned virtual machine is in the Stopped state by default.

3. Click the name of this virtual machine, and the page will redirect to the Container Platform’s virtual machine details page.

4. Click Start to successfully start the virtual machine.