Hi,
when i connect an usb stick to my carambola2 board, i see following syslog entry
Mar 29 12:06:07 carambola2 user.err vhusbdar7x9x: Failed to open the hub file descriptor, No such file or directory (/dev/bus/usb/001/001)
Same behaviour with avahi server and no-avahi server.
Do you have a /proc/bus/usb
Do you have a /proc/bus/usb/001/001 directory ? If you do not have that directory either you will need to install the usbcore/usb hub drivers in your openwrt build, i.e USB support in openwrt