A system and method for failsafe storage of real-time data, for example, relating to a hemodialysis or peritoneal dialysis treatment, includes: temporarily storing the real-time data in a ring buffer memory; pre-allocating a set of storage units of a storage medium, which is supplied with an operating voltage, for storing the real-time data in a file system; and based on the operating voltage of the storage medium being within a predefined reference range, transferring the real-time data from the ring buffer memory to the storage medium and storing the real-time data on a storage unit of the storage medium. In case of error, the integrity, authenticity, and availability of the stored real-time data are ensured.