How to Install and Use vnStat/vnStati for Real-Time Linux Network Monitoring

What is vnStat?

vnStat is a console‑based network traffic monitor for Linux and BSD that records traffic statistics for selected network interfaces using information provided by the kernel. It does not sniff packets, consumes minimal system resources, and can run without root privileges.

Key Features

Statistics persist across reboots

Monitor multiple interfaces simultaneously

Various output formats

Data can be sorted by hour, day, month, or week, and you can retrieve the last 10 days

Generate PNG graphs

Configurable monthly billing cycles

Very lightweight – low CPU and memory usage

Root not required

Dynamic unit selection (KB, MB, …)

Options such as –nl/–nolegend, –altdate, –headertext

JSON output support

Automatic interface bandwidth detection

Installation

Download and extract

Download the latest release from the official GitHub page or with wget:

# wget https://humdi.net/vnstat/vnstat-2.6.tar.gz

CentOS / RHEL / Fedora

# yum group install "Development Tools"
# yum install gd gd-devel sqlite-devel
# tar -xvf vnstat-2.6.tar.gz
# cd vnstat-2.6/
# ./configure --prefix=/usr --sysconfdir=/etc
# make
# make install

Debian / Ubuntu

$ sudo apt-get install build-essential gd gd-devel libsqlite3-dev
$ tar -xvf vnstat-2.6.tar.gz
$ cd vnstat-2.6/
$ sudo ./configure --prefix=/usr --sysconfdir=/etc
$ sudo make
$ sudo make install

Set up the service

Systemd:

# cp -v examples/systemd/vnstat.service /etc/systemd/system/
# systemctl enable vnstat
# systemctl start vnstat

Init.d:

# cp -v examples/init.d/redhat/vnstat /etc/init.d/
# chkconfig vnstat on
# service vnstat start

Verify installation

# vnstat
vnStat 2.6 by Teemu Toivola <tst at iki dot fi>

Configuration

Edit /etc/vnstat.conf to adjust options such as interface selection, database update interval, and output preferences.

Basic usage

Display current statistics:

# vnstat

Hourly statistics:

# vnstat -h

Daily statistics:

# vnstat -d

Show all available options:

# vnstat --help

Generating graphical reports with vnStati

vnStati is installed automatically with vnStat and can create PNG images of traffic data.

Example to generate a summary image for interface eth0:

# vnstati -s -i eth0 -o ~/network-log.png

Hourly report:

# vnstati -h -i eth0 -o ~/network-log.png

These tools provide valuable insight for monitoring, analyzing, and troubleshooting network usage on Linux systems.