These utilities will be in 4.3beta2. This includes /usr/share/doc/aufs.htm.
Puppy has been using Unionfs for sometime, previously when we used Aufs it was the 1.x series.
We will probably need to study Aufs2 to get the maximum benefit from it, but that can probably be a target for pup 4.4:
For example, it looks like there is potential for a clean shutdown, something that is an ongoing issue for Puppy.
Write directly to flash
The /usr/local/petget/installpkg.sh script is able to write directly to the save-layer when running Puppy on a Flash drive, in the case of Unionfs.
We never had this working properly with Aufs.
My Unipup concept, that I was working on sometime ago, runs Puppy totally in the initramfs and does not perform a switch_root. It seems that Aufs2 may be able to support building a layered filesystem within the initramfs -- this capability was a configure option when I compiled the kernel module, which I enabled.
EDIT, 6 SEPT 2009:
Some of the guys have been working on adding and removing SFS files without rebooting. They had this working with aufs1.
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