Troubleshooting Tip: Firmware upgrade failing with the error 'scsi_print_error[***]scsi error'

While loading the firmware or upgrading with the TFTP after the flash format with the article Technical Tip: Formatting and loading FortiGate firmware image using TFTP the following error can appear in the console:

Ver:05000006
Serial number:FG1KXXXX803304
RAM activation
CPU(00:000306e4 bfebfbff): MP initialization
CPU(01:000306e4 bfebfbff): MP initialization
CPU(02:000306e4 bfebfbff): MP initialization
CPU(03:000306e4 bfebfbff): MP initialization
CPU(04:000306e4 bfebfbff): MP initialization
CPU(05:000306e4 bfebfbff): MP initialization
CPU(06:000306e4 bfebfbff): MP initialization
CPU(07:000306e4 bfebfbff): MP initialization
CPU(08:000306e4 bfebfbff): MP initialization
CPU(09:000306e4 bfebfbff): MP initialization
CPU(0a:000306e4 bfebfbff): MP initialization
CPU(0b:000306e4 bfebfbff): MP initialization
Total RAM: 16384MB
Enabling cache...Done.
Scanning PCI bus...Done.
Allocating PCI resources...Done.
Enabling PCI resources...Done.
Zeroing IRQ settings...Done.
Verifying PIRQ tables...Done.
Boot up, timeout exit!
AhciIdentifyDevice: SCSI inquiry command failure.
set DMA transfer feature error!
timeout exit!
scsi_print_error[1150]scsi error
boot device capacity: 0MB.
Press any key to display configuration menu...
.............................
Invaild port number 255
scsi_print_error[1150]scsi error
You must format the boot device

After the message 'You must format the boot device', if the device is hanging and the SCSI error 'scsi_print_error' is visible, reboot the unit immediately.

Possible reasons for the error include:

• The upgrade may have been interrupted (e.g., power cut), leaving the boot partition unreadable, which can lead to a corrupted or missing boot flash.
• Internal storage or hardware failure (flash/SSD).
• An incompatible firmware image was flashed, meaning the device may fail to initialize storage properly.
• There could be BIOS/firmware corruption or a hardware fault. For example. the 'Invalid port number 255' system is probing for a nonexistent storage port.

When FortiGate cannot detect or access its boot storage (flash/SSD), the upgrade fails and the system cannot boot. The most likely cause is corrupted or failed flash memory.

If the same error appears after a hardware reboot, create a ticket with Fortinet TAC to check whether the unit requires an RMA.