Free online OVA to RAW converter

Virtualization tools may require a disk image instead of a complete appliance package, especially when attaching a VM disk to a custom QEMU/KVM machine or inspecting it with disk utilities. Converting an OVA to RAW extracts the virtual disk and changes its container format; it does not preserve the OVA's VM configuration as a separate RAW file.

What the OVA format is

An OVA is a TAR archive containing an OVF virtual-machine descriptor, one or more virtual disks, and sometimes a manifest or certificate. VMware vSphere, VMware OVF Tool, VirtualBox, and other hypervisors create or export OVA packages for distributing complete virtual machines.

The archive commonly contains a VMDK disk, an .ovf XML configuration file, and an .mf manifest. The OVF describes virtual hardware such as memory, CPUs, controllers, network adapters, and disk attachment order; it is not itself a disk image.

What the RAW format is

A RAW image is an unstructured sector-by-sector representation of a virtual disk. It contains guest partitions, filesystems, boot sectors, and free space, but no virtual-machine hardware definition or snapshot metadata.

RAW is supported by QEMU/KVM and many disk-analysis, partitioning, imaging, and recovery tools. Its simple layout avoids format-specific metadata and can be useful when attaching a disk directly to a custom VM or processing it with utilities that do not support VMDK.

The disadvantages are larger apparent size than sparse or dynamically allocated formats and the loss of features such as VMDK snapshots, backing files, and descriptor metadata.

How to convert OVA to RAW

The most reliable local method uses QEMU's qemu-img together with a TAR extractor.

1. Install QEMU for your operating system. The qemu-img command is included with most Linux distributions and is available in QEMU packages for Windows and macOS.
2. List the archive contents without extracting them:
   tar -tf appliance.ova
3. Extract the OVA into a separate directory:
   mkdir appliance
tar -xf appliance.ova -C appliance
4. Identify the virtual disk referenced by the OVF file. Inspect the extracted files and use qemu-img info to verify the disk format:
   qemu-img info appliance/disk.vmdk
5. Convert the disk to RAW, specifying the detected source format explicitly:
   qemu-img convert -p -f vmdk -O raw appliance/disk.vmdk appliance.raw
   Replace vmdk with the actual source format if the archive contains another supported disk type.
6. Check the resulting image:
   qemu-img info appliance.raw
   The reported format should be raw, and the virtual size should match the source disk.

If the OVA contains multiple disks, convert each disk separately and keep the original attachment order from the OVF file. Attach the resulting RAW files to a newly created VM with matching controller types and firmware settings; the OVF hardware configuration is not embedded in the RAW output.

For a browser-based conversion without installing software, use the free converter on 101convert.com. Large VM images can take substantial upload, processing, download, and local storage time.

Quality, compatibility, and limitations

This conversion normally preserves the guest disk's sectors exactly, but it does not repair filesystems, change partition tables, or make an operating system boot on different virtual hardware. A VM that used BIOS may require BIOS-compatible firmware after conversion, while a VM installed for UEFI may require UEFI and an EFI system partition.

Check the OVA manifest before modifying extracted files. Extraction alone does not change the disk, but editing or renaming package members can invalidate manifest checksums. If the archive contains a split or snapshot-based disk, convert the complete base-and-overlay chain as supported by the source format rather than selecting an arbitrary file.

RAW output can consume space close to its declared virtual capacity. Keep sufficient free space for the output and avoid overwriting the source. For sensitive virtual machines, perform the conversion locally because the image may contain credentials, application data, and deleted guest files.