Pi-Hole on a Raspberry Pi 1B

I seem to be running out of Raspberry Pis compared to the number of small projects I’m using them in. As it is, my Pi3 is torn between Kodi/LibreELEC and some animatronic duty and the Pi2 is being used in my wi-fi car which is currently a live project.

That’s why at some point I need to buy a Pi4!

I also wanted to bring back my Pi-Hole, which used to be on the Pi2. What to do? Well what I’ve done is re-install Raspberry Pi OS Lite and then Pi-Hole on my ancient Pi 1B, and so far it seems to be working fine, no heating or load issues as far as I can tell, so it feels good to get some more functionality out of that.

From what I’ve seen in the last 10 days is that temps run from around 49 - 53 °C, and the memory usage from around 10-15%, at least when I load up the admin screen; I’ll try to get some passive numbers for how it’s running when I’m not looking at the web admin page. For scale, it’s serving DNS responses for 10-15 clients at any time.

Currently, it’s rejecting around 10% of requests, which might actually be down on the last time I had it spun up.

For those who haven’t heard of Pi-Hole, it’s a DNS sinkhole system. Basically when you, or an application on your device want to contact an internet server, it makes a request to a DNS server to turn that domain name you typed in into the server’s IP address so it can go and connect to it (yes, massively simplified). So where’s the harm? Well, apps, especially advertising, tracking and other systems want to talk to servers to offload data, call home and such, eating bandwidth, slowing down browsers and such. What a DNS sinkhole does is return invalid DNS results or dump requests for domains it knows are for tracking or advertising (for example), effectively meaning you won’t be tracked and likely wont be served adverts on many pages. Often this will get past site code checks looking to see if you are using an ad-blocking extension, since this is happening upstream. In the case of the PiHole, sometimes it works, and sometimes it doesn’t.

It’s simpler to set up, and definitely works. It also gives you insight into the sheer number of these calls your devices are making every day - thousands of calls.