I already have few Raspberry Pi devices running Raspbian + my custom scripts. These device is internet connected and mounted at area which is hard to access, (e.g on top of a building)
Over the years, newer Raspbian version released or I created a newer custom image which I would like to deploy to all these devices easily.
Is there any example to remotely flash/update the OS images while the Pi is running live? (The scenario is like upgrading the Curiosity Mars land rover's OS from earth, then reboots it.)