22nd of August

Marks Rpi Cluster is still running 24/7. After 2 weeks of doing Einstein work, Rosetta has some work and most of the cluster (the Pi4's) have been running it exclusively. Hopefully things will level-out soon and it will return to the 50/50 split that its meant to be doing.

Debian released bullseye on the 14th of August, so now we're waiting on the Raspberry Pi Foundation to update to it. They already have a 5.10 kernel (which is what bullseye is using).

I haven't managed to do anything about my updated 3D printed cases as we've been in lock-down for 2 months now thanks to the Covid-19 delta strain. The lock-down has been extended for another month so its going to be a while yet.

Project issues & password-less logon

Marks Rpi Cluster continues to run 24/7. Due to some project issues we ran out of Einstein BRP4 work for a week and now Rosetta is out of work, fortunately Einstein now has work. That means the entire farm is running Einstein.

 

Password-less logon

I have been setting up password-less logon on all the Pi's. This is a bit more secure than using a password and saves me having to remember different passwords (all my support nodes have different passwords). Note that I run my Pi's headless (no screen or keyboard), so if you are using a desktop this won't be for you.

To do this you generate a certificate using Puttygen, which comes with the putty terminal emulator program. You do use putty to login to the Pi don't you? Once you've got that you save it on each Pi and then disable pam.

Login to the Pi. Type the following commands in:

mkdir ~/.ssh
nano ~/.ssh/authorized_keys

paste the key in and save the file.

 

Next we disable password prompting (you’ll still be prompted for a user name). Edit sshd_config:

sudo nano /etc/ssh/sshd_config

Find the line that says "UsePAM yes". To search in nano use Control-W and it will prompt for a string to find, or you can just scroll down the file. Comment it out by placing a # symbol in front and save it. And finally restart the ssh service.

sudo systemctl restart ssh

I saw some guides on the internet that talk about having to modify file permissions but its not needed. Now all I have to do to login to a Pi using putty is to tell it which one I want and when it prompts for a user name give it that and it automatically logs in.