View the summary of system load-related commands in Linux, and view load commands in linux

View the summary of system load-related commands in Linux, and view load commands in linux

How to check whether the system is loaded

W: View the overall load command of the system. It mainly focuses on the load average value, indicating the average load value of the system within 1 minute, 5, and 15 respectively. Generally, it is OK if it is smaller than the number of CPU resources on the server; the uptime can also be used to view the system load. The result is the same as the first line of the w command;

Cat/proc/cpuinfo: You can view the CPU information. Several processors are the CPUs;

Vmstat: Check where the load is located, the printed results mainly include process-related procs, memory, memory swap status swap, disk usage I/O, number of interruptions during the collection interval system, and CPU usage status CPU, focus on the number of processes running and waiting for cpu time slice r, number of processes waiting for resources B, the amount of data written from the swap zone to the memory si, the amount of data written from the memory to the swap zone so, and the amount of data written from the swap Zone the amount of data read by the device bi, the amount of data written from the block device bo, indicating the percentage of cpu time consumed by I/O wait wa;

Top: Dynamically monitor the resources occupied by the process. Place the most occupied system resources on the frontend to view the memory and CPU usage;

Sar: You can monitor the status of all resources in the system. sar-n DEV queries the network card Traffic history and sar-q queries the historical load. The most useful thing is to check the network card traffic. The traffic is too large: rxpck/s is greater than 4000, or rxKB/s is greater than 5000, it is likely to be attacked, need to capture packet analysis;

Free: View the total memory size and memory usage of the current system;

Ps: View the process, ps aux or ps-elf, which is often used with the pipeline operator to view the number of a process or it;

Netstat: Check the port. netstat-lnp is used to print the ports started by the current system. netstat-an is used to print the network connection status;

Tcpdump: The packet capture tool analyzes the data packets and knows which IP addresses are under attack. You can write the content to a specified file. 1. cap. The package content is displayed. The data flow is displayed on the-w screen;

Wireshark: Packet capture tool. You can temporarily use this command to view web requests on the current server