Problem with booting pfSense from USB Stick

On an appliance I reinstalled with pfSense I was facing a problem booting the system from an usb stick.

The system was not able to mount the partition correctly because it wasn't present at that time. For me this looks like a timing Problem. The system booted without a problem if I didn't connect the USB stick directly. I used an USB-hub while installation and booting from that USB stick while it was connected through this hub worked like a charm.

My Problem was similar to this. https://redmine.pfsense.org/issues/495

The fix was quite easy. I booted the system using the USB-hub and modified the loader.conf

I just had to add this at the end of the file:

kern.cam.boot_delay=10000

and everything worked fine even if I connected the USB stick directly to the appliance.

Hope this helps you if you're facing a similar problem.