you can run the command
ls -l /data
from an adb shell or from a terminal on the phone to check the symbolic links are present
after running the command, you should see a list, the items you are interested should have at the end:
dalvik-cache -> /system/sd/dalvik-cache
app-private -> /system/sd/app-private
app -> /system/sd/app
notice the -> indicating symlinks and the 'sd'
you can also run: busybox df -h
to check the /system/sd folder is being used