[GTALUG] RaspberryPi won't automount USB memory stick

[mwilson at Vex.Net]

>
>
> On 1/14/22 23:24, Kevin Cozens via talk wrote:
>> Greetings, all.
>>
>> I have an embedded system that uses a Raspberry Pi 3. I have it set up
>> and running with the latest Raspbian and all is well, almost. For some
>> reason the Raspbian system is not set up to automount memory sticks when
>> they are inserted in to a USB port on the machine.
>>
>> On another embedded system I needed to install the usbmount package to
>> get the system to automount a memory stick when it is inserted. I have
>> installed usbmount on the RPi but it still won't automount a USB memory
>> stick. The output from dmesg reports that it is seeing the insertion of
>> the USB memory device. The device is also reported under lsusb.
>>
>> Why is Raspbian not set up to automount a memory stick like is done on a
>> normal Linux based desktop? My desktop does it and I don't have an
>> usbmount package installed. How do I configure Raspbian to automount a
>> memory stick?
>>
>
> Normally it's something with systemd or udev rule flags. I had to google
> it as I'm
> not aware of all the rules. See if this works:
>
> Make sure it works  by changing MountFlags=slave to MountFlags=shared
> here:
>
> sudo nano /lib/systemd/system/systemd-udevd.service
>
> Not sure this helps,
> Nick

On a headless web server here, up-to-date Raspbian,  dmesg shows that
plugging in a USB flash drive creates a device  /dev/sda and /dev/sda1 . 
These devices disappear when the flash drive is unplugged.

The SD chip serving as the 'hard-drive' is present as /dev/mmcblk0 .

In Raspbian with the full GUI, something in the GUI catches a plugged-in
flash drive and mounts it under /media/username .  I don't know how. 
udev?