As part of our regular testing, we run power-fail tests. Whether it's during a read or a write, Yaffs is designed to preserve your existing data during a device power failure. And because Yaffs is open source, you can download the tests and run them yourself in the most severe conditions you expect the product to encounter. See:- http://www.yaffs.net/documents/yaffs-robustness-and-testing
