The cache cache is too large, and the CPU reaches more than 85%.
Command to release the data occupied by the system Cache: echo 3 > /proc/sys/vm/drop_caches
First line: From the operating system (OS) point of view:
The computer has a total of 4040896KB of physical memory, 1074496KB has been used , and 2966400 is available for free total=used+free
Shared: Memory shared by several processes
Buffers: The memory that is lived by the OS buffer ( written to disk ) . The buffer is used to store the data to be output to the disk ( block device )
Cache : store the data read from the disk . Buffer and cache are to improve IO performance and managed by OS
-buffer/cache : how much memory an application thinks the system is using; =used-buffers-cached
+buffer/cache : how much memory an application thinks the system has; =free+buffers+cached
The data read by the Free command is read from: cat /proc/meminfo