Vnstat

With this tool you can monitor data transfers occurring on a server.

Installation

Install as sudo

 apt-get install vnstat

Configuration

On first time startup, define each NIC to be monitored.

For a wired NIC:

 vnstat -u -i eth0

Wireless NIC:S

 vnstat -u -i wlan0

Monitor file transfer

Note that the program only updates every 10 seconds

Inspect file transfers. You may need to wait a while for the program to log enough data to display.

 vnstat

Example print:

  eth0 since 06/15/14

         rx:  104 KiB      tx:  354 KiB      total:  458 KiB

  monthly
                    rx      |     tx      |    total    |   avg. rate
    ------------------------+-------------+-------------+---------------
      Jun '14       104 KiB |     354 KiB |     458 KiB |    0.00 kbit/s
    ------------------------+-------------+-------------+---------------
    estimated        --     |      --     |      --     |

  daily
                    rx      |     tx      |    total    |   avg. rate
    ------------------------+-------------+-------------+---------------
        today       104 KiB |     354 KiB |     458 KiB |    0.07 kbit/s
    ------------------------+-------------+-------------+---------------
    estimated        --     |      --     |      --     |

RX = Download amount

TX = Upload amount

total = Total transfer amount

avg. rate = Average transfer speed

Live display

 vnstat -l

You can get additional help and information with the command

man vnstat

Another useful guide: http://humdi.net/vnstat/man/vnstat.html