VMDK file in OVF/OVA appear smaller than the original Virtual Disk

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

When exporting a virtual machine as an OVF or OVA package, the VMDK files may appear smaller than the original virtual machine disk because the export process uses compression.

Environment

VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x
VMware vCenter Server 7.X
VMware vCenter Server 8.X

Cause

• During OVF/OVA export, the VMDK is stored in a compressed (stream-optimized) format.
• This compression reduces the file size in the exported package.

Resolution

• This behavior is expected and does not indicate data loss.
• Once the OVF/OVA package is deployed, the VMDK files will be restored to their original provisioned size.

Example:

• • Original VMDK size on Virtual machine: 100 GB (thick provisioned).
  • Exported VMDK size in OVF/OVA package: 20 GB (compressed stream-optimized).
  • After OVF/OVA deployment, the VMDK is restored to 100 GB.

Additional Information

For more information about OVF/OVA packaging and stream-optimized VMDKs, refer to the following Broadcom documentation:
OVF File Format and OVF Templates (Broadcom TechDocs)

Japanese KB: OVF/OVAのVMDKファイルサイズが元の仮想ディスクよりも小さくなる