http://www.linuxquestions.org/questions/linux-software-2/gnu-tar-listed…
Ok, The problem the whole time was that both rdup and tar --listed-incremental detect every file on the cifs mount as being a new file. The reason for this is that the device number would change due to the automount. Tar has an option to get around this but it wasn't doing the trick. The temporary inode numbers being given to the mounted filesystems was the cause, they were being reassigned every time they were read. To get around this mount your cifs share with the "serverino" option.
server:share mountpoint cifs rw,mand,credentials=credential_file,serverino 0 0
That causes the windows machine to assign inode numbers to the files before cifs gets them, and thus they do not get reassigned. However, the windows server must support this and windows servers after 2000 do.
https://unix.stackexchange.com/questions/124531/linux-tar-listed-increm…
Lényeg: használj 'star'-t GNU tar helyett