AFP Permission issues after new FW update

sirozha wrote:
So, is this a standard mechanism of providing guest access in various Linux flavors or is this something that the RedyNAS team implemented?

The "nobody" user and "nogroup" group are standard Linux features (UID = GID = 65534). Mapping the OSX "guest" user to the linux "nobody" user is the default setup implemented by netatalk - so yes you can consider this "standard"

sirozha wrote:
According to that Wikipedia article, the stick bit - when set on a directory in Linuxv- restricts the renaming and unlinking of the files in that directory unless this is done by the root or owner. Is "unlinking" the same thing as "deleting"?

I would interpret it that way, though I've never really noticed the use of "unlink" in that article before. Here's the linux man page description which is perhaps a better description:

Linux man pages wrote:

A directory whose `sticky bit' is set becomes an append-only directory, or, more accurately, a directory in which the deletion of files is restricted. A file in a sticky directory may only be removed or renamed by a user if the user has write permission for the directory and the user is the owner of the file, the owner of the directory, or the super-user. This feature is usefully applied to directories such as /tmp which must be publicly writable but should deny users the license to arbitrarily delete or rename each others' files.

sirozha wrote:
In Mac OS X, there is a requirement that the owner of the file must has the write permission to the file in order to be able to delete it when the sticky bit is set on the enclosing directory. Is there such a requirement in Linux as well?

Depends - as the man page states: "A file in a sticky directory may only be removed or renamed by a user if the user has write permission for the directory..."

In that case, if the *file* does not have write access permission then it may still be deleted - the user is typically prompted to over-ride the lack of write permission, but that option may then be application dependent.