How to find out which process created a particular file

You can use smbstatus to list out the processes:

$ smbstatus -p

Samba version 3.0.33-0.18.el4_8.1
PID     Username      Group         Machine                        
-------------------------------------------------------------------
 9672   george        george        gb           (192.168.2.41)
14452   andrew        andrew        dev          (192.168.11.6)
17282   bob           bob           abcde        (192.168.2.11)

I know this is an old thread, but in case anyone else is having the same issue, I had...

What may be happening is that your process had a TCP port open when it crashed or otherwise exited without explicitly closing it. Normally the OS cleans up these sorts of things, but only when the process record goes away. While the process may not appear to be running any more, there is at least one thing that can keep a record of it around, in order to prevent reuse of its PID. This is the existence of a child process that is not detached from the parent.

If your program spawned any processes while it was running, try killing them. That should cause its process record to be freed and the TCP port to be cleaned up. Apparently windows does this when the record is released not when the process exits as I would have expected.