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.