Technical Tip: How to sanitize and securely wipe a FortiGate
Description
This article describes the steps required to sanitize or securely wipe the configuration from a FortiGate device before decommissioning it and removing it from the network.
Scope
FortiGate.
Solution
Perform a factory reset from the CLI.
execute factoryreset 
Perform a format of the hard disk from the CLI (for a device that comes with a hard disk).
execute erase-disk <diskname>
The 'How many times do you wish to overwrite the media?' prompt will appear: enter a number of times to overwrite the hard disk with random data in order to properly sanitize the disk by making previous data unreadable. In this example, the number used is 1.
This process performs a low-level format and overwrites each block with random data.
See the CLI reference: execute erase-disk.
Format the boot device from the CLI configuration and reload a new firmware image using TFTP. Refer to Technical Tip: Formatting and loading FortiGate firmware image using TFTP.
