Several customers reported problems while upgrading to FortiOS 5.4.1. FortGate 60D models did not boot up correctly after the upgrade. Fortinet is aware of the issue and mentioned it in the release notes:
The following 60D models have an issue upon upgrading to FortiOS 5.4.1. The second disk (flash) is unformatted and results in the /var/log/ directory being mounted to an incorrect partition used exclusively for storing the firmware image and booting.
- l FG-60D-POE
- l FG-60D
- l FWF-60D-POE
- l FWF-60D
To fix the problem, follow these steps. If you have not upgraded yet, you only need to perform step 6, otherwise start with step 1.
- Backup your configuration.
- Connect to the console port of the FortiGate device.
- Reboot the system and enter the BIOS menu.
- Format the boot device.
- Burn the firmware image to the primary boot device.
- Once the system finishes rebooting, from the CLI run «execute disk format 16». This will format the second flash disk.
- Restore your configuration.
Link to release notes:
http://docs.fortinet.com/d/fortios-5.4.1-release-notes