VirtualBox offers three primary methods to backup virtual machines (VMs): Export Appliance, Snapshot, and Copy VM’s Files.

Exporting a VM as an appliance creates a package containing all the files, configurations, and settings needed to recreate the VM. This package is saved as an .ova file and can be imported into VirtualBox or other virtualization software. Exporting a VM as an appliance is useful when you want to move or duplicate a VM to another host or virtualization software.

Taking a snapshot of a VM creates a point-in-time backup of the VM’s state, including memory, disk, and virtual machine settings. This feature is useful when you need to save a backup of a VM before making significant changes or updates to the system. If you need to restore a VM to a previous state, you can simply revert to the snapshot you created.

Copying a VM’s files is a simple way to create a backup of a VM. This method involves copying all the VM’s files to another location, such as an external hard drive or a network location. This method is useful when you want to create a backup of a VM that you can quickly restore to its previous state, without having to go through the process of exporting and importing the VM.

Each backup method has its advantages and disadvantages. Exporting a VM as an appliance is useful when you want to move a VM to another host or virtualization software, but it can take longer to export and import the VM. Taking a snapshot of a VM is quick and easy, but it can take up significant disk space. Copying a VM’s files is the simplest and fastest backup method, but it can be challenging to manage multiple backups and ensure they are up-to-date. Ultimately, the best backup method will depend on your specific needs and circumstances.