Quote Originally Posted by kl522 View Post
Aufs is more than just adding new files and modifying existing files. It is also able to "delete" or "hide" an existing files or directory. There is certain encoding or protocol to fully represent the modified file system structure. And therefore it is better to use the tools provided than to re-invent the wheel.
If you have to modify the whole structure, definitely yes. But is that really necessary for this particular use?

If we do something like

Code:
mount -t aufs -o dir=ramdisk=rw:persistent_image=rw:KNOPPIX=ro none /unionfs
What would go wrong if we did (evt. as a cron job)

Code:
rsync -ax ramdisk/ persistent_image
I just tested this with a couple of directories with a few files. Seemed to work in that case, at least.