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Most Linux users are familiar with the top command. Top shows you a list of processes on your system and provides a ton of useful information such as their CPU usage and owner. Unfortunately, this isn’t always enough data and many people don’t know where to turn next. This article covers three performance monitoring applications that show information top doesn’t tell you, and can greatly help in troubleshooting bottlenecks or just finding out more about your system. These utilities are iftop, iotop, and pv.