[root@mail ~]# free -m
             total       used       free     shared    buffers     cached
Mem:          3015       2769        246          0         51       1843
-/+ buffers/cache:        874       2141
Swap:         1983          0       1983
[root@mail ~]# free -m
             total       used       free     shared    buffers     cached
Mem:          3015       2809        206          0         51       1845
-/+ buffers/cache:        912       2103
Swap:         1983          0       1983
[root@mail ~]#