title: How to unmount a busy device
body: <p>I've got some samba drives that are being accessed by multiple users daily. I already have code to recognize shared drives (from a SQL table) and mount them in a special directory where all users can access them. </p>
  
  <p>I want to know, if I remove a drive from my SQL table (effectively taking it offline) how, or even is, there a way to unmount a busy device? So far I've found that any form of <code>umount</code> does not work. </p>
  
  <p>Ignoring the possibility of destroying data - is it possible to unmount a device that is currently being read? </p>