how to format flash disk

Hi,

Which flash are you talking about? 

Log flash:

exec formatlogdisk

It will force the Fortigate to reboot.

But, if you talk about the boot flash. You to reboot with the console port. Keep in mind, you have to download a new FortiOS inside your Fortigate after format. The device will not boot after. AND, you will loose all you fortigate's configuration. Be sure to have the FortiOS file and a TFTP server ready before formating a device.

------------ Console logs ------------

Please stand by while rebooting the system. Restarting system.

FortiGate-90D (20:14-02.28.2014) Ver:04000020 Serial number: FGT90D3XXXXXXXXX CPU(01): 900MHz Total RAM: 2GB Initializing boot device... Initializing MAC... nplite#0 Please wait for OS to boot, or press any key to display configuration menu..

: Configure TFTP parameters. : Review TFTP parameters. : Initiate TFTP firmware transfer. : Format boot device. : System information. : Boot with backup firmware and set as default. : Quit menu and continue to boot. : Display this list of options.

Enter C,R,T,F,I,B,Q,or H:

------------ End of Console logs ------------

Have a nice day,

Philippe