Clear Linux memory cache

Writing to this will cause the kernel to drop clean caches, dentries and inodes from memory, causing that memory to become free.

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
As this is a non-destructive operation, and dirty objects are not freeable, the user shoshould run "sync" first in order to make sure all cached objects are freed.

Reference:

Http://www.linuxinsight.com/proc_sys_vm_drop_caches.html

Author's "Dream footprints"