See if this can help you

  
      askubuntu.com
  
  
      
    
  

  How do I clean or disable the memory cache? 14



  software-recommendation, kernel, bash, memory



  asked by
  
  
    Forbidden Overseer
  
  on 12:25PM - 25 Jun 12


  
  
    
    
  
  


and this

  
      stackoverflow.com
  
  
      
    
  

  Linux : Disabling File cache for a process? 21



  linux, performance, caching, file-io



  asked by
  
  
    Vivek Goel
  
  on 06:35AM - 13 Feb 12