vnstat how to really deactivate interfaces?

Hi,

I use vnstat on all of my VPS and it looks like this:

root@vmware01:~# vnstat
Database updated: Sat Sep 13 14:11:26 2014

   eth0 since 08/28/14

          rx:  5.84 TiB      tx:  6.03 TiB      total:  11.87 TiB

   monthly
                     rx      |     tx      |    total    |   avg. rate
     ------------------------+-------------+-------------+---------------
       Aug '14      1.62 TiB |    1.67 TiB |    3.28 TiB |   10.53 Mbit/s
       Sep '14      4.22 TiB |    4.37 TiB |    8.59 TiB |   67.83 Mbit/s
     ------------------------+-------------+-------------+---------------
     estimated     10.07 TiB |   10.40 TiB |   20.47 TiB |

   daily
                     rx      |     tx      |    total    |   avg. rate
     ------------------------+-------------+-------------+---------------
     yesterday     26.99 GiB |   27.32 GiB |   54.31 GiB |    5.27 Mbit/s
         today    142.76 MiB |     707 KiB |  143.45 MiB |   23.00 kbit/s
     ------------------------+-------------+-------------+---------------
     estimated        --     |      --     |      --     |

But on my dedicated server it looks a bit different:

root@dedi:~# vnstat

                      rx      /      tx      /     total    /   estimated
 eth1: Not enough data available yet.
 eth0:
       Sep '14    696.64 MiB  /  621.60 MiB  /    1.29 GiB  /    3.06 GiB
     yesterday    370.61 MiB  /  317.96 MiB  /  688.57 MiB
         today    326.04 MiB  /  303.64 MiB  /  629.67 MiB  /    1.04 GiB

I assume that is because eth1 isn't in use and cannot create any data for vnstat. That is why I thought about deactivating it in vnstat. I already checked the man page, --help command and the configuration file. But I don't find a way to totally deactivate my eth1 interface for vnstat. I found this command vnstat -r --disable -i eth1, but it doesn't change anything.

Does anyone have an idea?