解决free -h cached 过大 问题

//先同步数据
sync 

//cache 释放：
//To free pagecache:
echo 1 > /proc/sys/vm/drop_caches

//To free dentries and inodes:
echo 2 > /proc/sys/vm/drop_caches

//To free pagecache, dentries and inodes:
echo 3 > /proc/sys/vm/drop_caches