journal

A log of changes written before applying them, replayed after a crash.

A journal records intended changes as CRC-checked entries before they are applied, so after a power cut complete entries are replayed and torn ones discarded.

Examples

Instead of rewriting a settings sector, the device appends a CRC-checked note of each change to a log and replays the complete notes at boot.
LittleFS, which the Arduino core can use for files, is built this way so a half-written last record is simply discarded after a power cut.