为了使缓存里的数据不丢失,之前先运行一下以下命令
sync
# 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