Не способный выполнить vnstat, если как корень в debian 7

На моем сервере, vnstat чтения от /proc/net/dev когда я использую -tr параметр:

iserv ~ # strace -e trace=file vnstat -tr 2
execve("/usr/bin/vnstat", ["vnstat", "-tr", "2"], [/* 46 vars */]) = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/libm.so.6", O_RDONLY)        = 3
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/libc.so.6", O_RDONLY)        = 3
open("/root/.vnstatrc", O_RDONLY)       = -1 ENOENT (No such file or directory)
open("/etc/vnstat.conf", O_RDONLY)      = 3
open("/proc/net/dev", O_RDONLY)         = 3
Sampling eth0 (2 seconds average)...open("/proc/net/dev", O_RDONLY)         =12 packets sampled in 2 seconds     
Traffic average for eth0

      rx            4 kbit/s             4 packets/s
      tx            0 kbit/s             1 packets/s

Я предложил бы, чтобы Вы проверили Вас /proc/net/dev полномочия. На Debian 6.0.7, это похоже на это:

iserv ~ # ll /proc/net/dev
-r--r--r-- 1 root root 0 14. Sep 14:19 /proc/net/dev