what i mean is that: the logical chunk number means the chunk id of one file(is the "struct yaffs_ext_tags.chunk_id"),and the physical chunk id means the chunk id of the whole nand flash. i wrote 12000 byte to my flash,the chunk size is 1984 byte and the spare size is 64 byte. when i use yaffs_add_find_tnode_0() to get the tnode 0 squencely.it shows the CHUNK whose "struct yaffs_ext_tags.chunk_id" is 5# is located after the CHUNK whose "struct yaffs_ext_tags.chunk_id" is 6.is this right? *> 0:-1 > 1:4864 > 2:4865 > 3:4866 > 4:4867 > 5:4869 > 6:4868 * ---- Regards, Ezio.