On Wednesday 16 October 2019 17:53:43 Valdis Klētnieks wrote: > and may cause problems if Linux says "currently using FAT 2", and the > disk is next used on a Windows 10 box that only looks at FAT 1.... You should use same algorithm which is used for FAT32. Primary FAT is first. And all operations are done on Secondary FAT and then is Secondary FAT copied to Primary. This is backward compatible with systems which operates only with first primary FAT. And other systems which see both FATs can benefit from redundancy/recovery. -- Pali Rohár pali.rohar@xxxxxxxxx