Content-type: text/html Man page of VNSTAT


Section: User Manuals (1)
Updated: JANUARY 2008
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vnStat - a console-based network traffic monitor  


vnstat [ -Ddhlmqrstuvw? ] [ -i interface ] [ -tr time ] [ --cleartop ] [ --config file ] [ --days ] [ --debug ] [ --disable ] [ --dumpdb ] [ --enable ] [ --help ] [ --hours ] [ --iface interface ] [ --live ] [ --longhelp ] [ --months ] [ --nick nickname ] [ --query ] [ --rebuildtotal ] [ --reset ] [ --short ] [ --showconfig ] [ --testkernel ] [ --top10 ] [ --traffic time ] [ --update ] [ --version ] [ --weeks ]  


vnStat is a console-based network traffic monitor. It keeps a log of hourly, daily and monthly network traffic for the selected interface(s). However, it isn't a packet sniffer. The traffic information is analyzed from the proc(5) filesystem. That way vnStat can be used even without root permissions.  


-d, --days
Show traffic for days.
-h, --hours
Show traffic for the last 24 hours.
-m, --months
Show traffic for months.
-s, --short
Use short output mode. This mode is also used if more than one database is available.
-t, --top10
Show all time top10 traffic days.
-w, --weeks
Show traffic for 7 days, current and previous week.
-tr time
Calculate how much traffic goes through the selected interface during the given time seconds. The time will be 5 seconds if a number parameter isn't included.
-l, --live
Display current transfer rate for the selected interface in real time until interrupted. Statistics will be shown after interruption if runtime was more than 10 seconds.
-i, --iface interface
Select one specific interface and apply actions to only it.
-q, --query
Force database query mode.
-u, --update
Update all enabled databases or only the one specified with -i parameter.
-r, --reset
Reset the internal counters in the database for the selected interface. Use this if the interface goes down and back up, otherwise that interface will get some extra traffic to its database.
Synchronize internal counters in the database with interface counters for the selected interface. Use this if the system is rebooted but interface counters aren't reseted. Such can occur when suspend to ram/disk is used.
--enable, --disable
Enable or disable updates for selected interface. Useful for interfaces that aren't always available, like ppp0. If the interface goes down it should be disabled in order to avoid errors. Add something like vnstat -r --disable -i ppp0 to the script that's executed when the interface goes down and vnstat --enable -i ppp0 to the up script.
-v, --version
Show current version.
Remove all top10 entries.
-?, --help
Show a command summary.
Show complete options list.
--nick nickname
Set the selected interfaces nickname as an alias the will be displayed in queries. Usage of -u is required to save the change.
--config file
Use file as config file instead of using normal config file search function.
Reset the total traffic counters and recount those using recorded months.
Test if the kernel boot time information always stays the same like it should or if it's shifting.
-D, --debug
Show additional debug output.
Instead of showing the database with a formated output, this output will dump the whole database in a format that should be easy to parse with most script languages. Use this for example with PHP, Perl or Python to make a custom webpage. The dump uses ; as field delimeter.

  active;1                        activity status
  interface;eth0                  name for the interface
  nick;inet                       nick (if given)
  created;1023895272              creation date in Unix time
  updated;1065467100              when the database was updated
  totalrx;569605                  all time total received MB
  totaltx;2023708                 all time total transmitted MB
  currx;621673719                 latest rx value in /proc
  curtx;981730184                 latest tx value in /proc
  totalrxk;644                    total rx kB counter
  totaltxk;494                    total tx kB counter
  btime;1059414541                system boot time in Unix time

Then follows 30 lines like the following


where d = days, 0 = day number in database (0 is today), 1077314401 date in Unix time, 559 = rx MB, 7433 = tx MB, 68 = rx kB, 557 = tx kB and 1 tells that vnStat has filled this value and it is in use.

  m;0;1078092000;48649;139704;527;252;1   (x12)
  t;0;1078351200;5979;47155;362;525;1     (x10)
  h;0;1078699800;118265;516545            (x24)

m = months, t = top10 and h = hours, all other fields are in the same order as in days except hours that doesn't have a separate kB value. For hours the forth and fifth fields have values in kB.



This directory contains all databases the program uses. Files are named according to the monitored interfaces.
Config file that will be used unless $HOME/.vnstatrc exists.


vnstat -u -i interface forces a database update for interface or creates the database if it doesn't exist. This is usually the first command used after a fresh install.

vnstat -u -i interface --nick nick gives interface the nickname nick and that information will be later included with queries.

vnstat -u -r --disable -i interface resets the internal counters of interface and disables it from being updated before enabled again with the --enable parameter. This feature is especially useful for interfaces like ppp0 that aren't always active.  


Updates needs to be executed at least as often as it is possible for the interface to generate enough traffic to wrap the kernel interface traffic counter. Otherwise it is possible that some traffic won't be seen. This isn't an issue for 64 bit kernels but at least one update every hour is always required in order to provide proper input. With 32 bit kernels the maximum time between two updates depends on how fast the interface can transfer 4 GB. Calculated theoretical times are:

    10 Mbit:  54 minutes
   100 Mbit:   5 minutes
  1000 Mbit:  30 seconds

However, for 1000 Mbit interfaces updating once every minute is usually a working solution.

Estimated traffic values are likely to be somewhat inaccurate if daily traffic is low because only the MB counter is used to calculate the estimate.

Virtual and aliased interfaces can't be monitored because the kernel doesn't provide traffic information for that type of interfaces. Such interfaces are usually named eth0:0, eth0:1, eth0:2 etc. where eth0 is the actual interface being aliased.  


Teemu Toivola <tst at iki dot fi>  


proc(5), ifconfig(8)




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Time: 03:41:18 GMT, September 24, 2010