Linux memory usage: 90%. Is it normal? -- Linux general technology-Linux technology and application information. For details, refer to the following section. Linux/Unix is different from windows in terms of memory management. Its management method is to make full use of the system memory, while windows uses a certain amount of virtual memory no matter how much memory is used.
Therefore, even if the memory usage of a linux system is % 90, it is normal. However, the memory usage does not reach 100%, because swap is enabled when the memory usage reaches one.
The Linux/Unix system is very stable. Although the memory usage is more than 90%, it can be ensured that the system does not need to be restarted for more than 365 days. For Linux systems, the load index for the last five minutes is the main indicator for evaluating the stress. For example, you can use the w command or top command to view numbers such as 2.20, 2.27, and 1.81.
The number of processes queued in five minutes, 10 minutes, and 15 minutes. As long as the first number is no more than 5 loads in five minutes, the system is healthy and no maintenance is required.
If this number is greater than 5, the system will usually slow down. There are several possible reasons:
1) if a program occupies a large amount of CPU, use the top command to check (to see if there is a fault such as the java program locking)
2) A program occupies a large amount of memory, making the memory really insufficient (this is the time when the memory needs to be added)
For example, because MySQL (the best combination with PHP) runs a database with a capacity of GB under a large load, resulting in insufficient memory, more physical memory needs to be inserted to the server.
3) if the disk system reads/writes fail, or the IO throughput error causes CPU load to rise, the disk needs to be guided to the single-user mode to scan and repair the disk. If the disk is not repaired properly, you can only replace the New hard disk.
Therefore, do not worry too much about the percentage of memory used by Linux/Unix systems. Generally, check the system load parameters. Original Author 6460646.
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