I have a Raspberry Pi 3+ and I boot Raspbian on an SD card sold with the Raspberry Pi 3+, I specify that the SD card was therefore already flash when purchased.
For a few weeks I had planned to make myself a NAS server with my own Python server and React application and stored all the data from my NAS on an external hard drive connected by USB to the Raspberry Pi 3+.
The problem is that if the hard disk is plugged in, the Raspberry Pi 3+ always wants to boot from the hard disk and not the SD card, which creates a big problem because there is no flash on the hard drive and it throws a console error on boot to say it can't find a boot.
Here is the error obtained when switching on with the external hard drive connected:
error 110 whilst initializing sd card
Priorities are supposed to be SD Card > USB, so I don't understand why it insists so much on connecting to the HDD and not the SD Card, also when I remove the HD from the RPi it boots normally to the SD Card and there is no problem.
I looked everywhere for a solution to this to change the boot order of the RPi but I can only find answers to do the opposite: boot an RPi from a USB flash drive, I also tried to mount the HD but the 'OS returns me that it is already mounted.
So I would like to understand what I have to change, if there is a solution that works with this OS? because I don't want an OS for NAS servers, I really want to do it myself and keep my current environment.
raspi-config
the boot options are limited to console or GUI display... I also looked at the advanced options and couldn't find anything to set priorities or find them I also can't update the tool to manage the configuration because I get an error trying that. what happens is that once the hard drive is connected, when booting I get this error:error 110 whilst initializing sd card
echo program_usb_boot_mode=0 | sudo tee -a /boot/config.txt
followed by a reboot? This should get written to the internal firmware on the reboot. Also, as you can assume, =1 turns it on. Also, I am not blindly giving you info from a website. I use it.