Tools to Monitor Linux Performance

Linux/Unix System administrators need to monitor and debug Linux System Performance problems every day. It is very hard to monitor and keep systems up and running without using proper tools or utilities. Below are some frequently used command line monitoring tools that might be useful for every Linux/Unix System Administrator. These commands are available under all flavors of Linux and can be useful to monitor and find the actual causes of performance problem.

1. lsof (List Open Files)
Lsof command used in many Linux/Unix like system that is used to display list of all the open files and the processes. The open files included are disk files, network sockets, pipes, devices and processes. One of the main reason for using this command is when a disk cannot be unmounted and displays the error that files are being used or opened. With this command you can easily identify which files are in use. The most common format for this command is.


2. tcpdump (Network Packet Analyzer)
tpdump is one of the most widely used command-line network packet analyzer or packets sniffer program that is used to capture or filter TCP/IP packets which are received or transferred on a specific interface over the network. It also provides a option to save captured packages in a file for later analysis. tcpdump is almost available in all major Linux distributions.


3. netstat (Network Statistics)
Netstat is a command line tool for monitoring incoming and outgoing network packets statistics as well as interface statistics. It is very useful tool for every system administrator to monitor network performance and troubleshoot network related problems.


4. top (Linux Process Monitoring)
Linux Top command is a performance monitoring program which is used frequently by many system administrators to monitor Linux performance and it is available under many Linux/Unix like operating systems. The top command used to display all the running and active real-time processes in ordered list and refreshes regularly. It display CPU usage, Memory usage, Swap Memory, Cache Size, Buffer Size, Process PID, User, Commands and much more. It also shows high memory and cpu utilization of a running processess. The top command is much useful for system administrator to monitor and take correct action when required.


5. vmstat (Virtual Memory Statistics)
Linux VmStat command used to display statistics of virtual memory, kernel threads, disks, system processes, I/O blocks, interrupts, CPU activity and much more. By default vmstat command is not available under Linux systems you need to install a package called sysstat that includes a vmstat program. The common usage of command format is.


6. iostat (Input/Output Statistics)
IoStat is simple tool that collects and shows system input and output storage device statistics. This tool is often used to trace storage device performance issues including devices, local disks, remote disks such as NFS.