Content
Data
license:
Version: 1.18 (in Debian 10)
Developer/Owner: Teemu Toivola
Short description:
The manual page and help for the vnstat Linux command. vnStat is a command-line network traffic monitoring tool. It keeps a log of the hourly, daily and monthly network traffic of the selected interface(s). Data traffic is not measured by capturing packets, but rather they are read from the proc(5) or sys file system, depending on availability, so vnStat can be used on most systems without root privileges.
The program consists of two parts. The vnstat command provides an interface for querying traffic data stored in network device-specific databases, while the vnstatd daemon is responsible for collecting and storing the data. Although the daemon process runs as a continuous service, it idles most of the time between data updates.
Man page output
man vnstatVNSTAT(1) User Manuals VNSTAT(1)
NAME
vnstat - a console-based network traffic monitor
SYNOPSIS
vnstat [ -Ddhlmqrstuvw? ] [ --cleartop ] [ --config file ] [ --create ] [ --days ] [ --delete ] [ --dbdir directory ] [
--debug ] [ --disable ] [ --enable ] [ --exportdb ] [ --help ] [ --hours ] [ --importdb file ] [ -i interface ] [ --iface
interface ] [ --iflist ] [ --json mode ] [ --live mode ] [ --locale locale ] [ --longhelp ] [ --months ] [ --nick nickname ]
[ --oneline mode ] [ --query ] [ --rateunit ] [ --rebuildtotal ] [ --reset ] [ -ru ] [ --savemerged ] [ --short ] [ --show‐
config ] [ --style number ] [ --sync ] [ --testkernel ] [ --top10 ] [ -tr time ] [ --traffic time ] [ --update ] [ --version
] [ --weeks ] [ --xml mode ]
DESCRIPTION
vnStat is a console-based network traffic monitor. It keeps a log of hourly, daily and monthly network traffic for the se‐
lected interface(s). However, it isn't a packet sniffer. The traffic information is read from the proc(5) or sys filesystems
depending on availability. That way vnStat can be used even without root permissions on most systems.
The implementation is divided into two commands. The purpose of the vnstat command is to provide an interface for querying
the traffic information stored in network interface specific databases where as the daemon vnstatd(1) is responsible for
data retrieval and storage. Although the daemon process is constantly running as a service, it is actually spending most of
the time sleeping between data updates.
OPTIONS
--cleartop
Remove all top 10 entries.
--config file
Use file as configuration file instead of using normal configuration file search functionality.
--create
Create database for interface specified with -i or --iface option.
-d, --days
Show traffic statistics on a daily basis for the last 30 days.
--dbdir directory
Use directory as database directory instead of using the directory specified in the configuration file or the hard‐
coded default if no configuration file is available.
-D, --debug
Show additional debug output.
--delete
Delete the database for the interface specified with -i or --iface and stop monitoring it.
--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. These
two options aren't needed when the daemon is used.
--exportdb
Instead of showing the database with a formatted output, this output will dump the whole database in a plain text
based architecture independent format. The output can be imported back using the --importdb option and can be used
for moving a database from one host to another. See the --importdb documentation below for an example. Using the out‐
put for scripting is possible but the outputs of --xml and --json are likely to be more suitable. The dump uses ; as
field delimiter.
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 MiB
totaltx;2023708 all time total transmitted MiB
currx;621673719 latest rx value in /proc
curtx;981730184 latest tx value in /proc
totalrxk;644 total rx KiB counter
totaltxk;494 total tx KiB counter
btime;1059414541 system boot time in Unix time
Then follows 30 lines like the following
d;0;1078696800;559;7433;68;557;1
where d = days, 0 = day number in database (0 is today), 1077314401 date in Unix time, 559 = rx MiB, 7433 = tx MiB,
68 = rx KiB, 557 = tx KiB 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 = top 10 and h = hours, all other fields are in the same order as in days except hours that doesn't
have a separate KiB value. For hours the forth and fifth fields have values in KiB.
-h, --hours
Show traffic statistics on a hourly basis for the last 24 hours.
--importdb file
Import a database from file which was previously exported using the --exportdb option. This can be used to transfer a
database between different architectures and hosts, as the database is architecture dependent and not compatible be‐
tween different architectures. First dump the database on one host, e.g. with vnstat -i ppp0 --exportdb >ppp0db.txt
and then import the text file on a different host using vnstat -i ppp0 --importdb ppp0db.txt
-i, --iface interface
Select one specific interface and apply actions to only it. For queries, it is possible to merge the information of
two or more interfaces using the interface1+interface2+... syntax.
--iflist
Show list of currently available interfaces.
--json mode
Show database content for selected interface or all interfaces in json format. All traffic values in the output are
in KiB. An optional mode parameter can be used for limiting the output to only selected information. Everything is
shown by default. Setting mode to 'h' will output only hours, 'd' days, 'm' months and 't' the top 10. This option
can also be used in combination with -l, --live and -tr options without mode having any effect to the output.
-l, --live mode
Display current transfer rate for the selected interface in real time until interrupted. Statistics will be shown af‐
ter interruption if the runtime was more than 10 seconds. An optional mode parameter can be used to select between
the displaying of packets per second (mode 0) and transfer counters (mode 1) during execution. --style can also be
used to affect the layout of the output. The output will be in json format if used in combination with --json option.
--locale locale
Use locale instead of using the locale setting specified in the configuration file or the system default if no con‐
figuration file is available.
--longhelp
Show complete options list.
-m, --months
Show traffic statistics on a monthly basis for the last 12 months.
--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 and the daemon may not be running during the set operation.
--oneline
Show traffic summary for selected interface using one line with a parseable format. The output contains 15 fields
with ; used as field delimiter. The 1st field contains the version information of the output that will be changed in
future versions of vnStat if the field structure changes. The following fields in order 2) interface name, 3) time‐
stamp for today, 4) rx for today, 5) tx for today, 6) total for today, 7) average traffic rate for today, 8) time‐
stamp for current month, 9) rx for current month, 10) tx for current month, 11) total for current month, 12) average
traffic rate for today, 13) all time total rx, 14) all time total tx, 15) all time total traffic. An optional mode
parameter can be used to force all fields to output in bytes without the unit itself shown.
-q, --query
Force database query mode.
-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. Not needed when the daemon is used.
--rebuildtotal
Reset the total traffic counters and recount those using recorded months.
-ru, --rateunit
Swap the configured rate unit. If rate has been configured to be shown in bytes then rate will be shown in bits if
this option is present. In the same way, if rate has been configured to be shown in bits then rate will be shown in
bytes when this option is present. Alternatively 0 or 1 can be given as parameter for this option in order to select
between bytes (0) and bits (1) regardless of the configuration file setting.
--savemerged
Write the end result of a database merge to the file mergeddb that can then be used as a new database if renamed. Top
10 traffic days isn't included in the merge and will start empty in the new database. The merge interface syntax is
documented in -i, --iface option.
-s, --short
Use short output mode. This mode is also used if more than one database is available.
--style number
Modify the content and style of outputs. Set number to 0 for a more narrow output, 1 for enabling bar column, 2 for
same as previous but with average traffic rate visible in summary and weekly outputs and 3 for enabling average traf‐
fic rate in all outputs where it is supported. 4 disables the use of terminal control characters in -l / --live mode.
--sync 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 reset. Such can occur when suspend to ram/disk is used. Not needed
when the daemon is used.
--testkernel
Test if the kernel boot time information always stays the same like it should or if it's shifting.
-t, --top10
Show all time top 10 traffic days.
-tr time
Calculate how much traffic goes through the selected interface during the given time seconds. The time will be 5 sec‐
onds if a number parameter isn't specified. The output will be in json format if used in combination with --json op‐
tion. However, in that case, the countdown before results isn't shown.
-u, --update
Update all enabled databases or only the one specified with -i parameter. Not supported when the daemon is running.
-v, --version
Show current version.
-w, --weeks
Show traffic for 7 days, current and previous week.
--xml mode
Show database content for selected interface or all interfaces in xml format. All traffic values in the output are in
KiB. An optional mode parameter can be used for limiting the output to only selected information. Everything is
shown by default. Setting mode to 'h' will output only hours, 'd' days, 'm' months and 't' the top 10.
-?, --help
Show a command option summary.
FILES
/var/lib/vnstat/
This directory contains all databases the program uses. Files are named according to the monitored interfaces. A
backup copy of each database is kept in a file starting with a . (dot character) and otherwise named according to the
original file.
/etc/vnstat.conf
Config file that will be used unless $HOME/.vnstatrc exists. See vnstat.conf(5) for more information.
EXAMPLES
vnstat Display traffic summary for the default interface or multiple interfaces when more than one is monitored.
vnstat -i eth0+eth1+eth3
Display traffic summary for a merge of interfaces eth0, eth1 and eth3.
vnstat -i eth2 --xml
Output all information about interface eth2 in xml format.
vnstat --json
Output all information of all monitored interfaces in json format.
vnstat -u -i eth0
Force a database update for interface eth0 or create the database if it doesn't exist. This is usually the first com‐
mand used after a fresh install if the daemon isn't used.
vnstat -u -i eth0 --nick local
Give interface eth0 the nickname "local". That information will be later later visible as a label when eth0 is
queried. The database will also be updated when this command is executed or created if the database doesn't exist.
vnstat -i eth2 --delete
Delete database of interface eth2 and stop monitoring it.
RESTRICTIONS
Updates needs to be executed at least as often as it is possible for the interface to generate enough traffic to overflow
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 GiB. 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 usable solution if faster updates can't be used.
Estimated traffic values are likely to be somewhat inaccurate if daily traffic is low because only the MiB counter is used
to calculate the estimate.
Virtual and aliased interfaces cannot 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.
Using long date output formats may cause misalignment in shown columns if the length of the date exceeds the fixed size al‐
location.
AUTHOR
Teemu Toivola <tst at iki dot fi>
SEE ALSO
vnstatd(1), vnstati(1), vnstat.conf(5), proc(5), ifconfig(8), units(7)
version 1.18 MARCH 2018 VNSTAT(1)
Help output
vnstat --help
vnstat --longhelp vnStat 1.18 by Teemu Toivola <tst at iki dot fi>
-q, --query query database
-h, --hours show hours
-d, --days show days
-m, --months show months
-w, --weeks show weeks
-t, --top10 show top 10 days
-s, --short use short output
-u, --update update database
-i, --iface select interface (default: eth0)
-?, --help short help
-v, --version show version
-tr, --traffic calculate traffic
-ru, --rateunit swap configured rate unit
-l, --live show transfer rate in real time
See also "--longhelp" for complete options list and "man vnstat".
[...]
vnStat 1.18 by Teemu Toivola <tst at iki dot fi>
Query:
-q, --query query database
-h, --hours show hours
-d, --days show days
-m, --months show months
-w, --weeks show weeks
-t, --top10 show top 10 days
-s, --short use short output
-ru, --rateunit swap configured rate unit
--oneline show simple parseable format
--exportdb dump database in text format
--importdb import previously exported database
--json show database in json format
--xml show database in xml format
Modify:
--create create database
--delete delete database
-u, --update update database
-r, --reset reset interface counters
--sync sync interface counters
--enable enable interface
--disable disable interface
--nick set a nickname for interface
--cleartop clear the top 10
--rebuildtotal rebuild total transfers from months
Misc:
-i, --iface select interface (default: eth0)
-?, --help short help
-D, --debug show some additional debug information
-v, --version show version
-tr, --traffic calculate traffic
-l, --live show transfer rate in real time
--style select output style (0-4)
--iflist show list of available interfaces
--dbdir select database directory
--locale set locale
--config select config file
--savemerged save merged database to current directory
--showconfig dump config file with current settings
--testkernel check if the kernel is broken
--longhelp display this help
See also "man vnstat".
Related Content
- 5 views