TL;DR: How do I force the sdcard to always be mounted on /dev/sda?
When I boot my arduino with an sdcard installed but without a usb drive, the webpage stored in sd is accessible. Additionally, I can upload sketches with webpages and it will update the file on the sdcard.
If I plug in a USB drive, it continues to work normally. However, if I remove power and allow it to boot completely while the USB drive is connected, it will mount the USB at /dev/sda, which is where it looks for the webpage. The Arduino appears to always mount USB first if it is booting up.
How can I change this? I need the webpage to be stored on the sd and still allow the arduino to boot from with a USB drive connected for secondary file storage.
Any ideas