VNSTAT(1)

NAME
vnstat - a console-based network traffic monitor

SYNOPSIS
vnstat [-5bDedhlmqstvy?] [--add] [--alert output exit type condition limit unit] [--begin date] [--config file] [--days [limit]] [--dbdir directory] [--dbiflist [mode]] [--debug] [--end date] [--fiveminutes [limit]] [--help] [-hg] [--hours [limit]] [--hoursgraph] [-i interface] [--iface interface] [--iflist [mode]] [--json [mode] [limit]] [--limit limit] [--live [mode]] [--locale locale] [--longhelp] [--months [limit]] [--oneline [mode]] [--query] [--rateunit [mode]] [--remove] [--rename name] [-ru [mode]] [--setalias alias] [--short] [--showconfig] [--style number] [--top [limit]] [-tr [time]] [--traffic [time]] [--version] [--xml [mode] [limit]] [--years [limit]] [interface]

DESCRIPTION
vnStat is a console-based network traffic monitor. It keeps a log of 5 minute interval, hourly, daily, monthly and yearly network traffic for the selected interface(s). However, it isn't a packet sniffer. The traffic information is read from the proc(5) or sys filesystems depending on availability resulting in light use of system resources regardless of network traffic rate. That way vnStat can be used even without root permissions on most systems.

Functionality is divided into two commands. The purpose of the vnstat command is to provide an interface for querying the traffic information stored in the database whereas the daemon vnstatd(8) is responsible for data retrieval, caching and storage. Although the daemon process is constantly running as a service, it is actually spending most of its time sleeping between data updates.

OPTIONS

--add
    Create database entry for interface specified with -i or --iface option. The daemon can be running during this operation and will automatically start monitoring the interface without a restart within SaveInterval minutes if configuration option RescanDatabaseOnSave is enabled. Otherwise the daemon needs to be restarted in order for the added interface to be monitored.

--alert output exit type condition limit unit
    Depending on values of given parameters, show alert, use different exit status or a combination of both when configured situation is met.

    output parameter takes a number from 0 to 3 and controls when, if at all, the command will result in output. '0' never produces output, '1' always produces output, '2' shows output only when usage estimate exceeds limit and '3' shows output only when limit is exceeded.

    exit parameter takes a number from 0 to 3 and controls the exit status of the command. '0' always uses exit status 0, '1' always uses exit status 1, '2' uses exit status 1 if usage estimate exceeds limit but otherwise exit status 0 and '3' uses exit status 1 if limit is exceeded but otherwise exit status 0.

    type parameter defines to which time range type usage the limit is compared against. Available options: 'h', 'hour', 'hourly', 'd', 'day', 'daily', 'm', 'month', 'monthly', 'y', 'year', 'yearly'.

    condition parameter defines if limit is compared to received (rx), transmitted (tx), total or estimated usage of these three. Available options: 'rx', 'tx', 'total', 'rx_estimate', 'tx_estimate', 'total_estimate'.

    limit is a greater than zero integer without decimals which defines the traffic usage limit using the unit defined with the unit parameter. unit accepts the following options: 'B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB'. Usage must exceed limit in order for the alarm to activate. Exactly the same usage as limit does not raise the alarm.

    Estimate calculation isn't limited to the estimate options in condition parameter but can also be achieved by using the estimate option in output or exit parameters. Missing or invalid parameters will result in --alert specific help output being shown.

-b, --begin date
    Begin the list output with a specific date / time defined by date instead of the begin being selected based on the number of entries to be shown. If date isn't available in the database then the closest later date will be used. date supports the following formats: YYYY-MM-DD HH:MM, YYYY-MM-DD and "today". This option can only be used with --json , --xml and list outputs.

--config file
    Use file as configuration file instead of using automatic configuration file search functionality.

-d, --days [limit]
    Show traffic statistics on a daily basis for the last days. The length of the list will be limited to 30 entries unless configured otherwise or unless the optional limit parameter is used. All entries stored in the database will be shown if limit is set to 0.

--dbdir directory
    Use directory as database directory instead of using the directory specified in the configuration file or the hardcoded default if no configuration file is available.

--dbiflist [mode]
    List interfaces currently in the database. If mode is not defined or is set to 0 then the output will use a one line verbose format. If mode is set to 1 then the output will contain one interface per line. See also --iflist.

-D, --debug
    Show additional debug output.

-e, --end date
    End the list output with a specific date / time defined by date instead of the latest date / time in the database. If date isn't available in the database then the closest earlier date will be used. date supports the following formats: YYYY-MM-DD HH:MM and YYYY-MM-DD. This option can only be used with --json , --xml and list outputs. The top list also requires --begin to be used at the same time with this option.

-5, --fiveminutes [limit]
    Show traffic statistics with a 5 minute resolution for the last hours. The length of the list will be limited to 24 entries unless configured otherwise or unless the optional limit parameter is used. All entries stored in the database will be shown if limit is set to 0.

-h, --hours [limit]
    Show traffic statistics on a hourly basis. The length of the list will be limited to 24 entries unless configured otherwise or unless the optional limit parameter is used. All entries store in the database will be shown if the limit is set to 0.

-hg, --hoursgraph
    Show traffic statistics on a hourly basis for the last 24 hours using a bar graph followed by a table representing the numerical data.

-i, --iface interface
    Select one specific interface and apply actions to only it. For database queries, it is possible to merge the information of two or more interfaces using the interface1+interface2+... syntax. All provided interfaces must be unique and must exist in the database when the merge syntax is used. Optionally, depending on the InterfaceMatchMethod configuration setting, interface can be replaced with alias previously set using --setalias. Merge syntax isn't supported when alias is used. The -i, --iface option is optional and interface can be used as parameter on the command line for selecting the used interface even without the option being explicitly used.

--iflist [mode]
    List currently available interfaces. If mode is not defined or is set to 0 then the output will use a one line verbose format. If mode is set to 1 then the output will contain one interface per line. See also --dbiflist.

--json [mode] [limit]
    Show database content for selected interface or all interfaces in json format. All traffic values in the output are in bytes. An optional mode parameter can be used for limiting the output to only selected information. Everything is shown by default. Setting mode to 'f' will output only 5 minute resolution entries, 'h' hours, 'd' days, 'm' months, 'y' years and 't' the top days. Alternatively or in combination with mode an optional limit parameter can be used to limit the number of entries in the output. The --json option can be used in combination with -l, --live and -tr options without mode or limit having any effect to the output. The jsonversion field in the output contains the API version information. It will be changed only when the names or structures of previously existing content gets changed. In comparison, the vnstatversion field exists only as extra information.

--limit limit
    Set the maximum number of shown entries in list outputs to limit. Usage of --limit overrides the default list entry limit values and the optional limit parameter given directly for a list query. All entries stored in the database will be shown if limit is set to 0. --limit can also be used to control the length of --json and --xml outputs.

-l, --live [mode]
    Display current transfer rate for the selected interface in real time until interrupted. Statistics will be shown after 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 configuration file is available.

--longhelp
    Show complete options list.

-m, --months [limit]
    Show traffic statistics on a monthly basis for the last months. The length of the list will be limited to 12 entries unless configured otherwise or unless the optional limit parameter is used. All entries stored in the database will be shown if limit is set to 0.

--oneline [mode]
    Show traffic summary for selected interface using one line with a parsable format. The output contains 15 fields with ; used as field delimiter. The 1st field contains the API version information of the output that will only be changed in future versions if the field content or structure changes. The following fields in order 2) interface name, 3) timestamp for today, 4) rx for today, 5) tx for today, 6) total for today, 7) average traffic rate for today, 8) timestamp for current month, 9) rx for current month, 10) tx for current month, 11) total for current month, 12) average traffic rate for current month, 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.

--remove
    Delete the database entry for the interface specified with -i or --iface and stop monitoring it. The daemon can be running during this operation and will automatically detect the change.

--rename name
    Rename the interface specified with -i or --iface in the database with new name name. The new name cannot already exist in the database. This operation doesn't cause any data loss. The daemon should not be running during this operation.

-ru, --rateunit [mode]
    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, mode with either 0 or 1 can be used as parameter for this option in order to select between bytes (0) and bits (1) regardless of the configuration file setting.

--setalias alias
    Set alias as an alias for the selected interface to be shown in queries. The set alias can be removed by specifying an empty string for alias. The daemon can be running during this operation.

-s, --short
    Use short output mode. This mode is also used when more than one interface is available in the database and no specific interface is selected.

--showconfig
    Show current configuration using the same format as the configuration file itself uses.

--style number
    Modify the content and style of outputs. Set number to 0 for a narrower output, 1 for enabling bar column, 2 for same as previous but with average traffic rate visible in summary output and 3 for enabling average traffic rate in all outputs where it is supported. 4 disables the use of terminal control characters in -l / --live mode.

-t, --top [limit]
    Show all time top traffic days. The length of the list will be limited to 10 entries unless configured otherwise or unless the optional limit parameter is used. All entries stored in the database will be shown if limit is set to 0. When used with --begin and optionally with --end, the list will be generated using the daily data instead of separate top entries. The availability of daily data defines the boundaries the date specific query can access.

-tr, --traffic [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 specified. The output will be in json format if used in combination with --json option. However, in that case, the countdown before results isn't shown.

-v, --version
    Show current version.

--xml [mode] [limit]
    Show database content for selected interface or all interfaces in xml format. All traffic values in the output are in bytes. An optional mode parameter can be used for limiting the output to only selected information. Everything is shown by default. Setting mode to 'f' will output only 5 minute resolution entries, 'h' hours, 'd' days, 'm' months, 'y' years and 't' the top days. Alternatively or in combination with mode an optional limit parameter can be used to limit the number of entries in the output. The xmlversion field in the output contains the API version information. It will be changed only when the names or structures of previously existing content gets changed. In comparison, the vnstatversion field exists only as extra information.

-y, --years [limit]
    Show traffic statistics on a yearly basis for the last years. The list will show all entries by default unless configured otherwise or unless the optional limit parameter is used. All entries stored in the database will also be shown if limit is set to 0.

-?, --help
    Show a command option summary.

FILES

/var/lib/vnstat/
    Default database directory.

/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 -i eth0 --setalias local
    Give interface eth0 the alias "local". That information will be later visible as a label when eth0 is queried.

vnstat -i eth2 --remove
    Delete database entries for interface eth2 and stop monitoring it.

RESTRICTIONS
Updates need 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. With 32-bit interface traffic counters, the maximum time between two updates depends on how fast the interface can transfer 4 GiB. Note that there is no guarantee that a 64-bit kernel has 64-bit interface traffic counters for all interfaces. Calculated theoretical times are:
    10 Mbit: 54 minutes
    100 Mbit: 5 minutes
    1000 Mbit: 30 seconds

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 allocation.

AUTHOR
Teemu Toivola <tst at iki dot fi>

SEE ALSO
vnstatd(8), vnstati(1), vnstat.conf(5), proc(5), ifconfig(8), units(7)