Circumference is a miniaturised datacentre-in-a-box, complete with programmable power distribution and sequencing, instrumentation, cooling, networking, and a switchable remote console — all packaged in custom-designed desktop enclosures which eliminate cable clutter and give you complete control over the hardware inside.

Chris Dent has a blog post about netbooting the Circumference.

https://www.crowdsupply.com/ground-electronics/circumference
https://groundelectronics.com/products/circumference/

In my previous posting on the Circumference I said that I wanted to get the eight Raspberry Pi nodes to netboot from the front end processor so I could more easily manage the nodes on which I wanted to install nova-compute. This post provides a very quick update on those explorations. Newer Pi 3 B have firmware that can allow them to netboot without any SD card in place, but it requires a fair bit of set up. I was struggling to make headway, never seeing bootpc packets from the nodes. Turns out a newer firmware is needed. Andrew Back, from Ground Electronics the company building the Circumference, pointed to a useful cookbook blog post, Network Booting a Raspberry Pi 3 from an Ubuntu Server, that includes pointers to the new firmware. That got me a bit further. I’m now able to see some nodes, sometimes choosing to send bootpc packets and otherwise talking to the network.[…]

https://anticdent.org/circumference-25-netbooting.html
https://anticdent.org/circumference-25-beta.html
https://www.crowdsupply.com/ground-electronics/circumference/updates/openstack-progress-with-network-booting