 Combined with a cloud computing environment or other writable medium, to maintain persistence, an OS booted from a write-locked SD card is robust, rugged, reliable, and impervious to permanent corruption.If the running OS degrades, simply turning the machine off and then on returns it back to its initial uncorrupted state and thus is particularly solid.The SD card installed OS does not require removal of corrupted components since it was write-locked though any written media may need to be restored.