Here are four highly used daily monitoring tools for Linux that can help you diagnose system problems accurately and quickly.

1. iotop

If you want to know how much your precious I/O resources are being used by certain processes, use IOTOP. The iostat command is also used to check THE I/O status. However, the iostat command monitors the I/O status at the system level, while the iotop command monitors the I/O status of a process.

2. htop

Htop is an enhanced version of traditional TOP with better visuals and easier understanding of the current state of the system. You can clearly see the usage status of each CPU core, not as obscure as top. Similarly, memory usage is clear. Not only does it have traditional percentage data, but it also uses a bar chart to show CPU and memory metrics, which is much more readable than top. Moreover, the operation is more convenient, for example, the process can be terminated without entering the process ID, and multiple processes can be terminated at once. Htop also has many convenient operations. It is recommended to replace TOP.

3. IPTraf

IPTraf is a powerful tool for diagnosing network problems. It can monitor all network traffic on the system. Filters can be set for the specified port and transport type. IPTraf is like a lightweight Wireshark. With IPTraf, you can do many delicate things, such as statistical segmentation of traffic by overall packet size:

Tcpdump and Tshark have similar functions to IPTraf, but IPTraf is easier to use and provides menus.

4. Monit

Monit is a very flexible tool with many configurations and support for different types of threshold and performance alarms. Monit allows you to monitor processes, ports, files, and other targets, and you can set a dynamic alert mode. For example, if you want to monitor a process to make sure it is running, restart it if it dies, and send an alarm if it hangs multiple times. Such requirements can be easily addressed by Monit. Monit also has a lightweight Web interface:

Whether it’s managing a single server or multiple servers, Monit is an extremely simple and efficient monitoring tool.