Online server is not a fixed time every day, there will be at least a Cached memory is clear, at the same time lead to read IO spurt, for 3 minutes or so, in some time inside business N times, the response time of the elongated
The following is the disk IO screenshots, the output of the SAR - pd,

The following screenshots is memory, the output of the SAR - r,

The following is the/proc/meminfo2 minutes contrast figure



Why Linux should clear the content of the Inactive, Active also cleared? And under the system of the/proc/sys/vm/drop_caches is always 0, is system kernel parameters can be controlled? Please help to look at, thank you.