I built a new headless VM server this year and used TinyPilot to install Proxmox, an open-source hypervisor and web interface for managing VMs.

And mind you, for each HDMI dongle and UDC you have, those are essentially “seats” that you are adding, or “users” in IP KVM terminology. i.e. these can all be active at the same time, so you could have 2 users each accessing a different system without stomping on each other. A lot of the commercial IP KVM implement this sort of thing with a single capture device, and single UDC, and then a big HDMI switch to choose which system it is connected to. i.e. a “single user” device. KVM Over IP switches can support a variety of Digital and Analog video connector types. Video support is dependent on the switch - some IP KVMs offer support for VGA, DVI, HDMI, and DP simultaneously, while others may only support VGA.

Production-ready

The TinyPilot Power Connector allows the Pi to receive 3 Amps of power through its USB-C port without losing USB OTG functionality. HDMI to CSI adapter: works with all Raspberry Pis, including Raspberry Pi Zero W and 2 W. It’s also much faster, with extra low latency (MJPEG and H.264/WebRTC stream).

The main thing to consider for the type of video your KVM Over IP switch needs to support is what type of video do your servers / PCs output, and what type of video will any future servers / PCs output. Unlike with standard local KVM switches, you do not need to consider what signal your monitor supports because you will be connecting to the IP KVM through a separate PC. The managed server and its BIOS can be accessed using a regular VNC client which supports JPEG compression.Note: From further discussions with Max, I’ve learned that Pi-KVM does support builds without soldering or breadboards. uStreamer: a super-fast video streamer 🔗︎

IP KVM Switches are ideal for managing mission-critical systems. BIOS-level access allows you to solve complex problems efficiently and restore service before downtime hurts productivity... no server-resident software is required, so server performance and reliability are never compromised. Select models also allow remote control of connected monitored PDUs. Individual ports on the KVM can be assigned to a port on the PDU: cycle or power on/off connected servers without leaving the KVM session screen. Panel array mode enables user to monitor multiple servers from single screen at the same time - each selected server's video output appears in a separate panel - users can easily select the number of panels to view A ready-to-use OS that can be created just by running make build and installed to an SD-card using make install. The hardware can be made in half an hour and without soldering. This two-PC-capable KVM switch uses HDMI for the connection to the primary monitor's input, as well as to the outputs from your connected systems. (Credit: Kyle Cobian) uStreamer reduced my latency from 10 seconds down to ~600 milliseconds. That was a huge leap forward but still a noticeable delay. I told Max I was interested in funding uStreamer further if he could find ways to improve performance, so we got to chatting.

Open Source

The biggest limitation of this setup is power. Relying on the target computer for power means that when the target shuts down, the Pi suffers an unexpected power cut. Our testing gear comprised a Viotek GNV27DB curved gaming monitor, two Windows 10-based desktop mini-PCs we recently reviewed (the Geekom IT8, and the Beelink GK Mini), and a standard wired gaming keyboard and mouse from Logitech. In turn, we set up each KVM device and switched between or among PCs 10 times, using a stopwatch to measure the switchover time and then averaging the results. To test the audio and video quality, we played a 4K HD movie (our old testing stalwart, Tears of Steel) on each PC through each KVM switch in turn to our Viotek monitor. We also watched the same video with the PCs direct-connected to the monitor to see if any perceptible difference. By default the OS runs in read-only mode, as an embedded system should. This prevents damage to the memory card due to a sudden power outage.