I currently have a working Raspbian installation on my Raspberry Pi that I use to read my car's diagnostic info using OBD2 (by setting up a Wifi hotspot on boot and opening a socket relaying data to an OBD serial interface)
However, I can't properly shut down the Pi, because it runs off the car's 12V. So in order to prevent filesystem corruption I would like to make the OS read-only.
I didn't find anything useful on Google unfortunately. I'd like to have something working like a live CD (squashFS image). Can I just make a squashFS image of my current root partition?
What about log files and such? Do I need to have some kind of RAM filesystem for the system temp files or something?