title: cocoa how to get the ALREADY mounted unmountable disk
body: <p><strong>NSWorkspaceDidMountNotification</strong> works well to get the information of just mounted disk.
  But how can I get the information of <strong>already</strong> mounted disks before my app start?</p>
  
  <p>command line: "diskutil list" and "diskutil info /" works but there should be a simple programmatically method there.</p>
  
  <p>searched result of "DiskArbitration" or "VolumeToBSDNode example" don't work, IOkit difficult.  </p>
  
  <p>BTW, anyone recommend of using this?
  [NSWorkspace getFileSystemInfoForPath:isRemovable:isWritable:isUnmountable:description:type:]</p>