Linux performance Monitoring-utility commands (excerpt)

1.top--linux Process Monitoring

Top:linux Monitor run time Current time number of logged on users CPU memory load average system load (1 minutes 5 minutes 15 minutes "generally less than 1, higher than 5 will be hard system performance, need to view the process in detail)

2.vmstat--Virtual Memory Statistics

The Linux vmstat command is used to display virtual memory statistics, Kernerl threads, disks, system processes, I/O modules, interrupts, CPU activity, and so on. By default, you need to install a Sysstat package on a Linux system before you can use the Vmstat command.

lsof--to list open files

The lsof command, like many Linux/unix system commands, is used to display all open files and processes. These open files include disk files, network sockets, pipelines, devices, and processes. The main reason for using it is that when you unmount the file system, if there are any open files in the file system, the operation will usually fail, so you can find out which processes are in use by lsof.

4.tcpdump--Network Packet Analyzer

Tcpdump is the most widely used command line-the network packet Analyzer or packet sniffer program-to capture or filter TCP/IP packets received or transferred from a specific interface on the network. It also saves the captured package to a folder. Tcpdump can be used on all major Linux distributions.

5.netstat--Network Statistics

Netstat is a command-line tool for monitoring incoming and outgoing network packet information and interface information statistics. It is useful for system administrators to use it to monitor network performance and troubleshoot network-related issues.

6.htop--linux Process Monitoring

Htop is a more advanced interactive and real-time Linux process monitoring tool. This command is very similar to the top command, but it is more versatile, such as friendly user interface process management, shortcut keys, vertical and horizontal view processes, and more. Htop is a third-party plug-in tool that you need to install on a Linux system using the Yum Package management tool.

7.lotop--Monitoring Linux disk I/O

Lotop is similar to the top command and the Htop program, but it has statistical capabilities to monitor and display disk I/O in real time. This tool is useful for precise processes and for discovering high-usage read/write processes.

8.iostat--Input/Output statistics

Iostat is a very simple tool for collecting and displaying system input and output storage device statistics. This tool is typically used to track performance issues with storage devices, including devices, local disks, remote disks such as NFS.

Linux performance Monitoring-utility commands (excerpt)