VDI

VirtualBox Disk Image

VDI is a virtual disk image file format used primarily by Oracle VM VirtualBox to store guest operating system data.

What is VirtualBox Disk Image?

The VDI format was developed by Oracle (originally Innotek, later Sun Microsystems) as the native virtual hard disk format for VirtualBox. It encapsulates a complete virtual file system, storing data either as a fixed-size allocation or dynamically expanding as the guest OS writes more data. VDI files are widely used in software development, testing, and virtualization environments where multiple operating systems need to run on a single host machine.

Advantages

Supports dynamically expanding storage to save physical disk space
Integrates natively and performs efficiently within Oracle VM VirtualBox
Allows snapshotting to save and revert to specific virtual machine states
Easily convertible to other hypervisor formats like QCOW2 or VMDK

Limitations

Limited native compatibility with non-VirtualBox hypervisors without conversion
Dynamic VDI images can suffer from fragmentation over time, requiring manual compaction
Can grow rapidly if the guest OS generates excessive temporary data

How to open VirtualBox Disk Image files

Oracle VM VirtualBox QEMU Virtual Machine Manager (virt-manager) Libguestfs

Common use cases

Running secondary operating systems inside VirtualBox for software testing
Isolating legacy applications on modern host hardware
Creating portable development environments that can be moved across machines
Safe browsing and malware analysis within a virtual sandbox

VDI converters

VDI → qcow2

VDI → QCOW2

Explore other formats

KML Geographic Data File TIFF image Rich Text Format DOC Document GZ Archive Matroska Video (MKV) TXT Plain Text File BMP image SVG Image QCOW2 Disk Image EMF Image PDF document

Frequently asked questions

A VDI file is a virtual hard disk image used by Oracle VM VirtualBox to store the file system and data of a virtual machine.

You can open and run a VDI file directly inside Oracle VM VirtualBox by attaching it to a virtual machine, or mount it using tools like QEMU.

Yes, you can convert VDI files to other virtual disk formats such as QCOW2 using command-line utilities or conversion services like ConvertX.

They can be either fixed-size or dynamically allocated, where the file grows on the host storage as the guest operating system consumes more space.