I have a RUT955 (FW Version 00.07.00) with a SD card used for memory expansion and an USB stick used for a samba share.
The memory expansion works well: the block device /dev/mmcblk0p1 is mounted on /overlay and seems it is working.
The USB stick itself seems to work as well. The block device /dev/sda1 is mounted on /mnt/sda1.
But when I try to configure a shared directory in the Samba server (Services > Network Shares > Shared Directories), the destination path always jumps to the path /overlay. I choose the path /mnt/sda1 (USB stick), save the configuration, switch the view to another page (e.g. USB Tools > General). When I siwtch back to the view Network Shares, the path is changed to /overlay again.
Am I doing something wrong? Or what´s going on here?