Clear Linux I/O cache

Do this:



echo 3 > /proc/sys/vm/drop_caches


In some case, you may get a out of memory error due to memory used up even by I/O cache.  Such kind of error definitely is a bugs but this may cause your process failure.  I came across in KVM on ubuntu 12.04.

You may do this after backup or restore since these commands usually fill up I/O cache.