2015-12-03
free -m cat /proc/sys/vm/drop_caches #sync将所有未写的系统缓存区write to disk，包含已修改的i node、已延迟的块IO和读写映射 sync #drop_caches默认是0，提供了三个选项操作 1 清空页缓存 2 清空inode和目录树缓存 3 清空所有的缓存 echo 3 > /proc/sys/vm/drop_caches cat /proc/sys/vm/drop_caches free -m
[root@sdb2 ~]# free -m total used free shared buffers cached Mem: 2883 2812 71 0 157 2514 -/+ buffers/cache: 140 2743 Swap: 4095 2 4093 [root@sdb2 ~]# cat /proc/sys/vm/drop_caches 0 [root@sdb2 ~]# sync [root@sdb2 ~]# echo 3 > /proc/sys/vm/drop_caches [root@sdb2 ~]# cat /proc/sys/vm/drop_caches 3 [root@sdb2 ~]# free -m total used free shared buffers cached Mem: 2883 92 2791 0 0 10 -/+ buffers/cache: 81 2802 Swap: 4095 2 4093