Permanently Disable Touchpad - Lubuntu 16.04

I believe so. You'll have to use a few commands and make a startup script, but you know the former and the latter isn't hard to do.

First, run xinput list. Your output should be similar to the following:

zachary@MCServer:~$ xinput list
⎡ Virtual core pointer                      id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎣ Virtual core keyboard                     id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Power Button                              id=7    [slave  keyboard (3)]

If you can, unplug your mouse beforehand.

Now you need to find the ID of the trackpad. Use the main ID (not the one that's indented under a main item) for now. If it turns out that the main item covers both the mouse and touchpad, choose the corresponding sub-ID.

Now you need to run

xinput set-prop DEVICEID "Device Enabled" 0

For example, if I wanted to disable my mouse, I'd use 2 for DEVICEID.

Plug in your mouse and make sure it works and the touchpad doesn't. If the mouse doesn't work, then run

xinput set-prop DEVICEID "Device Enabled" 1

and run the first command again with the sub-ID instead.

To make this apply on startup, you need to make it a startup command. Open Startup Applications (or the equivalent on your desktop environment) and add the first command.

Alternatively, you could just disconnect the trackpad internally.

Yes it is very easy. Blacklist the touchpad module.

To find out what module it is, you can run

grep -iA 2 touchpad /proc/bus/input/devices

Here you will see something like elan or synaptic

And then

ls $(find /lib/modules/$(uname -r) -type d -name mouse)

To see all the mouse & touchpad modules for the current kernel. The touchpad will have i2c or touch in the name, mouse modules will have mouse or usb. Cross reference these two results

Edit: I recently figured out how to reliably get the name of the driver in use with a convoluted command, which terdon simplified nicely for me:

grep -hriPo 'DRIVER=\K.+' /sys 2>/dev/null | while read driver; do [ -e /lib/modules/$(uname -r)/kernel/drivers/input/mouse/"$driver"* ] && echo $driver; done

I'm guessing your touchpad module is synaptics_i2c.ko. You will omit the .ko when writing the blacklist

check you got the right module

sudo modprobe -r synaptics_i2c

immediately the touchpad will die, if you got the correct module. Now to prevent it from ever being loaded:

Create a file in the /etc/modprobe.d directory with the .conf extension, containing the words blacklist synaptics_i2c (replace with your module name, excluding .ko). For example

echo "blacklist synaptics_i2c" | sudo tee /etc/modprobe.d/blacklist-touch.conf

(but check that the filename you choose does not already exist)

Run synclient TouchpadOff=1 to remove the touchpad.