Error when running vmkfstools --writezeros "Not a supported filesystem type"

Products

• VMware vSphere ESXi

Issue/Introduction

An administrator for security or decommissioning purposes may attempt to zero out a VMDK on the command line using vmkfstools --writezeros, receives the error "Not a supported filesystem type"

Environment

ESXi (all versions)

Cause

This command, vmkfstools --writezeros, is only supported on VMFS file systems. If you try and run this command from any other filesystem, namely NFS, it will fail with this error.

Resolution

This error is expected.

Please seek an alternative method to secure wipe your VMDK 

Here are two examples:

• Move the VMDK (using advanced svmotion) to a local VMFS volume (if possible) and try the command again before deleting the VMDK
• Attach the VMDK to another VM that has the capability of using an internal tool on the OS to write zeros to the VMDK.