How to replace OpenSSH with Dropbear on Raspberry Pi OS Buster

OpenSSH is the default SSH server/client on Raspberry Pi OS (formerly known as Raspbian), but on systems where RAM is at a premium – the Raspberry Pi 3 Model A+ or Raspberry Pi Zero W, for example – saving memory can be important. One simple way to do this is by replacing OpenSSH with a similar but more lightweight SSH program called Dropbear. Here’s how:

First, install Dropbear:

sudo apt-get install dropbear

Answer yes at the prompt by pressing enter. Next, edit the Dropbear configuration file with:

sudo nano /etc/default/dropbear

and change the line

NO_START=1

to

NO_START=0

save the file with ctrl-o > enter > ctrl-x.

Now stop OpenSSH (if you have accessed your Pi with SSH, you won’t lose your connection):

sudo systemctl stop sshd.service

Now enable and start Dropbear with:

sudo systemctl enable dropbear.service

followed by:

sudo systemctl start dropbear.service

At this point it is safe to disable OpenSSH with

sudo systemctl disable sshd.service

Optionally, reboot your Raspberry Pi:

sudo reboot

Next time you SSH to your Pi you will probably see a message that says:

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

This is because, when it was installed, Dropbear generated new SSH keys. Edit your ~/.ssh/known_hosts file to delete the line containing the IP address of your Pi and SSH to your Pi again.

Once you’re sure everything is working properly, and if you want to, you can remove openssh-server:

sudo apt-get purge openssh-server

Enable tap-to-click on Synaptics touchpads in Lubuntu 19.10 Eoan Ermine

Banner image for Lubuntu 19.10 Eoan Ermine
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Update 2020-05-07: This also works with Lubuntu 20.04 LTS Focal Fossa.

I’ve searched the internet looking for a way to enable tap-to-click on Synaptics touchpads in Lubuntu 19.10 Eoan Ermine and have tried the .conf file variants those searches throw up. None of these has worked for me.

It turns out enabling tap-to-click is much more straightforward than the internet would suggest. To enable tap-to-click, open QTerminal (or the terminal of your choice) and enter the following command:

sudo apt install xserver-xorg-input-synaptics

Enter your administrator password and, once the package has finished installing, reboot your computer. Tap-to-click should now be enabled.