How to set a password to boot FreeNAS, or make it impossible to boot without an inserted USB flash drive?

Question

FreeNAS

Task: There is a PC with FreeNAS, it is necessary to provide protection from booting it by anyone other than the administrator.
I see 2 options: set a password to boot FreeNAS, or make FreeNAS boot only if there is a USB flash drive, so that it can be turned off during boot.
The system itself is now installed on a USB flash drive, but when it is turned off, the system does not work.
The BIOS password is not suitable, because it is easy to reset it.

Answer 1

Absolute protection does not exist, but in most cases it is enough to encrypt the partitions and the bootloader on the flash drive, which contains the password for them, directly in the init script in the initramfs