One of my colocated servers has to be low power, so I went with an 8 gig Raspberry Pi 4 with two USB-3 attached 8 TB disks, mirrored. It runs NetBSD, and it runs well - it serves backup MX, DNS, a SearxNG instance, an rsync destination for backups, et cetera.
SearxNG runs decently, but it takes a lot of memory and requires the CPU's full attention, which means background compiling can cause search timeouts (they can be niced, but when things are pushed to swap, you have no choice to wait for them to be swapped back), so I got a 16 gig, 8 core, 2.4 GHz Orange Pi 5 which'll replace the Raspberry Pi 4. It's very quick, relatively cheap ($120), and takes less power than I thought it would.
In many instances where I want to run a physically tiny computer, Raspberry Pi Zeros are small, can run on 1/2 amp at 5 volts, and won't overheat. However, their lack of ethernet makes using them a bit clunky. On the other hand, there're these little NanoPi Neo devices that are adorably cute, very tiny, take as little power as the RPi Zero (or even less), and fully functional with ethernet and a heat sink that makes mounting them super easy.
Another application I've had is a hardware VPN device which 100% prevents leakage because the computer can't communicate with anything but the hardware device. For this I'm using NanoPi R2S because they're tiny, they have two physical gigabit ethernet ports and you can buy them with a cute little case, so they're practically ready-to-go products that only need an SD card put in to be 100% ready to go.
I have other projects, but these are some I've already done.
One of my colocated servers has to be low power, so I went with an 8 gig Raspberry Pi 4 with two USB-3 attached 8 TB disks, mirrored. It runs NetBSD, and it runs well - it serves backup MX, DNS, a SearxNG instance, an rsync destination for backups, et cetera.
SearxNG runs decently, but it takes a lot of memory and requires the CPU's full attention, which means background compiling can cause search timeouts (they can be niced, but when things are pushed to swap, you have no choice to wait for them to be swapped back), so I got a 16 gig, 8 core, 2.4 GHz Orange Pi 5 which'll replace the Raspberry Pi 4. It's very quick, relatively cheap ($120), and takes less power than I thought it would.
In many instances where I want to run a physically tiny computer, Raspberry Pi Zeros are small, can run on 1/2 amp at 5 volts, and won't overheat. However, their lack of ethernet makes using them a bit clunky. On the other hand, there're these little NanoPi Neo devices that are adorably cute, very tiny, take as little power as the RPi Zero (or even less), and fully functional with ethernet and a heat sink that makes mounting them super easy.
Another application I've had is a hardware VPN device which 100% prevents leakage because the computer can't communicate with anything but the hardware device. For this I'm using NanoPi R2S because they're tiny, they have two physical gigabit ethernet ports and you can buy them with a cute little case, so they're practically ready-to-go products that only need an SD card put in to be 100% ready to go.
I have other projects, but these are some I've already done.