How to clear out the cache being used
Linux has a good memory management feature that will use up any “extra” RAM you have to cache stuff. This section of the memory being used is SUPPOSED to be freely available to be taken over by any other process that actually needs it. This will eventually reduce the performance of your system. Following command will help you.
[root@l3admins]# free -m
total used free shared buffers cached
Mem: 3990 3181 809 0 448 2228
-/+ buffers/cache: 503 3486
Swap: 9452 0 9452
Use the following command as root to clear cache from your machine.
sync; echo 3 > /proc/sys/vm/drop_caches
This will only support Kernels 2.6.16 and newer.
The above command will cleared out the cache in your machine.