[xolox]

I suspect they are referring to using a Raspberry Pi and using a micro SD card as the main storage mechanism. This is known to be a bad combination that will fail at an unfortunate time, sooner rather than later.

Personally I boot my Raspberry's using netboot (DHCP via dnsmasq) and NFS. However I don't run Home Assistant on a Raspberry, it runs on the "server" (headless machine) that's serving NFS .