查看占用情況:free命令
[root@data60 ~]# free -m
total used free shared buffers cached
Mem: 7872 7175 696 0 8 138
-/+ buffers/cache: 7028 843
Swap: 8191 16 8175
Mem行是物理內存占用——
其中實際內存占用=used-buffers-cached
清理緩存
echo 1 > /proc/sys/vm/drop_caches
http://www.cnblogs.com/52linux/archive/2012/03/08/2385399.html