Power Failure Protection of SSD
SSD Problems caused by power failure: Generally power failure would cause 3 main problems to SSD when PC runs. 1. Mapping table might get lost because there is no enough time to update and store it. Usually SSD manufacturers do not provide users with tools to recover mapping table. Thus SSD will become undetectable to host and only method is to return the drive to manufacturer for repairing. And SSD vendors will reproduce the drives by firmware which will get all data on SSD lost. 2. SSD mostly deploy DDR or SDRAM as the cache on board. Once power fails, all data in cache will be lost because both DDR and SDRAM are non-volatile media. And these data have never been transferred into NAND flash yet because R/W speed of DDR is far higher than NAND Flash. However host will consider that data writing has already been finished. In this way power failure causes data loss. 3. Power failure results in new nominal bad blocks. ECC of controller checks 256bit data in row and column, a...