Usually, I don't bother or I drag whatever kit I'm wrangling over to a display and keyboard.  Turns out those micro-HDMI connectors are not awesome and vary considerably in physical dimension until persuaded to the male connector spec.   And now there are 4 of them to contend with without disturbing the USB ports.

I decided my sanity requires more.  Cycling power is not calming to my personal being.  I'm fine with fixing broken, as long as I know just how that works.  The console is quite special in Unix for this specific purpose.  Just ask the kernel.

To make this work in a more "appliance" way - I am using a Pi3B to perform a very useful function - separate from the running cluster.  This will provide the usual "lights out" function that defines a proper appliance.

1. Serial console - FT4232H Quad HS USB-UART/FIFO used to provide simple connectivity to four nodes over a single USB port.  I'm using putty to create console logging files and have debug access when the network is unusable.

2. Fan control -  The Pi 4B nodes need moving air and temperature monitoring. Not alot of air, but some. Drives the temps down an easy 20 degress C.

3. Physical sensor data collection.  I'm planning on using Mycodo on this node for the PID cooling functions - Fan control and enclosure temp.  

This is the way to go with multiple node deployments - you get a log of the boot process and all the messages for that eventual calamity will be captured in putty logs.   The other useful thing is catching the cloud-init config.   The root certs are presented on the console - if that matters to you.  With a putty console, I can log that output.