[Yaffs] Yaffs2 Question

Hi all,

I have some questions.
1.       For yaffs2, I know there is a checkpoint strategy. The yaffs will write the current status of the system into block before the next mount. So I wonder do the yaffs rewrite that old chunks stored the information every time or it will use new chunks for every “checkpoint”?
2.       For the update file, can I said that any change in a file will lead to write a new object header in the end? If not, what situation will lead to update a new object header?

Thank you.
Alex