I’ve been wanting to create a Pi cluster for ages and with the new Pi Zero 2 that uses the Pi 3 chip and is 5x faster, I am thinking about exploring this path again but with a specific purpose: Home Assistant. Even if it’s on Pi 4’s, that’s cool, but I don’t know if it’s even possible to do this.
Has anyone tried to do an HA cluster (on any Pi device)? I can really see the benefits from a failsafe perspective since I’ve had HA die on me a few times and realized how reliant I am upon this system. But I’m not sure how it would deal with the USB stick or anything or if there is really any benefit or not.
But creating a cluster of Pi Zero sized boards with Pi 3 power could be a really beefy little system!
What exactly would the benefit of doing this, besides technical curiosity ?
I mean, I get the failover aspect. But that’s very hard to achieve in typical HA scenarios where some externally managed local network is involved (zwave, zigbee, etc). Probably not impossible using things like secondary controllers (or whatever they’re called in Zigbee, coordinators ?). But also probably not worth the hassle unless your HA installation is really mission critical. Failover system also need to be maintained. Just have a second Pi4 somewhere in a drawer and if things fail catastrophically, just swap the hardware and pull your latest backup off your NAS / cloud.
Distributing HA core components all over multiple Pis seems really counterproductive. It just increases the probability of failure and increases maintenance. Instead of dealing with the probabilities of a single SD card failing, you now have 5 or 10 to look after. And on the CPU side, honestly, I don’t see the value either. On my Pi3, HA uses on average around 3% CPU power. And if you have CPU intensive workloads, then using something from the x86 world is probably a better choice anyway.
Then again I never understood why people do RPi clusters in the first place, so I might be biased
Aside from the core OS on the SD, it would all be SSD.
Much of it is technical curiosity, some is failsafe and as I integrate more and more into my system I may outgrow a single Pi system, so I thought this would be an interesting project.
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