Step-by-Step Guide to Convert VirtualBox VMs to KVM for Improved Performance

How to Convert VirtualBox VMs to KVM on Linux for Enhanced Virtualization Performance

In this guide, you’ll learn how to convert VirtualBox VMs to KVM on Linux.

KVM offers superior performance for Linux virtual machines.

Converting to KVM enhances virtualization efficiency and reduces resource usage.

Follow these steps to migrate your VirtualBox virtual machines to KVM on Linux.

Why KVM is much Better and Faster for Linux VMs

KVM is faster because it integrates directly with the Linux kernel, providing high performance with minimal overhead.

Hardware virtualization support allows KVM to take advantage of Intel VT or AMD-V, offering better CPU utilization.

Low Latency is achieved with KVM’s ability to run VMs without significant delays, providing near-native performance.

Better resource allocation allows KVM to handle multiple VMs efficiently with flexible CPU, memory, and disk management.

Security is improved as KVM benefits from the Linux security features like SELinux, AppArmor, and seccomp.

Open-source and free, KVM provides a cost-effective solution with robust community support and frequent updates.

Wide compatibility ensures KVM works with various Linux distributions and supports both Linux and Windows guests.

1. 1. Shut Down the VirtualBox VM

   Make sure the VirtualBox VM is powered off before proceeding with the conversion.

2. 2. Convert the VMDK to QCOW2 Format

   Use qemu-img to convert the VirtualBox VMDK disk to KVM’s QCOW2 format:

   qemu-img convert -f vmdk -O qcow2 your-vm.vmdk your-vm.qcow2

   -f vmdk tells qemu-img that the input file is in VMware’s VMDK format.

   -O qcow2 tells it to convert the image into KVM’s QCOW2 format, which supports snapshots and compression.

3. 3. Create a New KVM Virtual Machine

   Use either virt-manager (GUI) or virt-install (CLI) to create the KVM VM.

   With virt-manager (GUI):
   – Create a new VM
   – Select “Use an existing disk image”
   – Choose the converted your-vm.qcow2 disk file
   – Set OS type and other parameters accordingly

   See: Getting Started with Virt-Manager

   With virt-install (CLI):

   virt-install \
   --name your-vm \
   --memory 2048 \
   --vcpus 2 \
   --disk path=/path/to/your-vm.qcow2,format=qcow2 \
   --import \
   --os-type=linux \
   --os-variant=generic \
   --network bridge=virbr0 \
   --graphics spice
       

4. 4. Boot and Test the KVM VM

   Boot the newly created KVM VM and verify that it works properly. You may need to:

   • Remove VirtualBox tools
   • Install qemu-guest-agent or virtio drivers for better performance
   • Reconfigure networking if needed

   See: Enabling KVM Acceleration on Linux

5. 5. Virt Manager Getting-Started Guide

   Getting-Started with KVM QEMU Virtualization on GNU/Linux

   Virt Manager Quick-Start Guide

   Getting-Started with Virt Manager on Linux Tutorial.