Evey time you connect to your xbox, the FTP server will output the following:
QUOTE
Connecting to Xbox
Connected to 192.168.1.100 Port 21
220-Client IP: 192.168.1.10
220-Local Date and Time: Feb 17, 2006 13:55:40
220-
220-Server Stats
220-Current Users: 1 Total Connections: 2
220-Total Received: 179 Bytes, 0 Files, 0 Failed
220-Total Sent: 5400 Bytes, 0 Files, 0 Failed
220-Drive C Used: 250.70MB Free: 249.22MB Total: 499.92MB
220-Drive D Used: 0.00MB Free: 0.00MB Total: 0.00MB
220-Drive E Used: 3,675.30MB Free: 1,206.33MB Total: 4,881.63MB
220-Drive F Used: 2,112.03MB Free: 22.48MB Total: 2,134.52MB
220-Drive X Used: 5.33MB Free: 744.56MB Total: 749.89MB
220-Drive Y Used: 0.06MB Free: 749.83MB Total: 749.89MB
220-Drive Z Used: 720.86MB Free: 29.03MB Total: 749.89MB
220 UnleashX FTP Server ready.
...
...
On top of that, you can send a command like:
FREESPACE F, FREESPACE G...etc.