PuTTY and ssh keys

To use PuTTY on windows to ssh into a linux machine using a key rather than a password…

On your windows machine

Run the puttygen program included in the PuTTY package and generate your key.


Save the private key (my filename was testprivatekey.ppk) and the public key (I used testpublickey.txt)

Set up the connection in PyTTY, adding your private key.


At the moment, this will fail to connect using the key as we havent copied onto the other machine, so use your password to log in.

On your Linux machine

Copy your public key to this machine and convert to openssh format using ssh-keygen

$ ssh-keygen -i -f testpublickey.txt > puttypublickey.sshformat

Now append the public key to your list of authorised keys

$ cat puttypublickey.sshformat >> .ssh/authorized_keys

In future, your password will not be needed.


Chromium Browser on Linux cannot see Chromecast

When you try casting from the Chromium Browser, you click on cast… but it cannot find any devices.


A setting needs changing, go to the settings address “chrome://flags/#load-media-router-component-extension” and select “enable”.

Reducing disk writes

Under systemd, jounald writes the system log to disk every five minutes. To reduce the number of writes to disk, this can be changed to once a day, by changing the line



in the file /etc/systemd/journald.conf.




So, you set an environmental variable called PATH in your .bashrc.

This gives you goodies like tab completion of the name and not needing to type in the full path for a program.

If you use a CDPATH environmental variable, you get the same magic when using cd to change directories.

Make sure to include to include “.” in the path, so that cd looks in the current directory.