Mastering Embedded Linux Programming

Filesystems for managed flash

As the trend towards managed flash technologies continues, particularly eMMC, we need to consider how to use it effectively. While they appear to have the same characteristics as hard disk drives, some NAND flash chips have the limitations of large erase blocks with limited erase cycles and bad block handling. And, of course, we need robustness in the event of losing power.

It is possible to use any of the normal disk filesystems but we should try to choose one that reduces disk writes and has a fast restart after an unscheduled shutdown, typically provided by a journal.

Flashbench

To make optimum use of the underlying flash memory, you need to know the erase block size and page size. Manufacturers do not publish these ...