Checksum mismatch while updating
For each file, ex FAT uses two separate 64-bit length fields in the directory: the Valid Data Length (VDL) which indicates the real size of the file, and the physical data length.
ex FAT is also supported in a number of media devices such as modern flat panel TVs, Some vendors of flash media, including USB pen drives, compact flash (CF) and solid state drives (SSD) are shipping from the factory with some of their high capacity media pre-formatted with the ex FAT file system.
Most of the vendors signing on for licenses of ex FAT are either for embedded systems or device manufacturers that produce media that will be preformatted with ex FAT.
The entire File Allocation Table (FAT) family, ex FAT included, is used for embedded systems because it is lightweight and is better suited for solutions that have low memory and low power requirements, and can be implemented in firmware.
ex FAT and the rest of the FAT family of file systems does not use indexes for file names, unlike NTFS which uses B-trees for file searching.
When a file is accessed, the directory must be sequentially searched until a match is found.