title: why I can not permanently remove a file from linux?
body: <p>Today,I encounter a very tough problem which cost me nearly 6 hours.</p>
  
  <p>When I remove a file called ha_wan.conf using <strong>rm -rf ha_wan.conf</strong> command under /etc directory,Success.When I use <strong>ls -al</strong> command to see the result,The file disappear.</p>
  
  <p>But when I reboot the linux system,same file named ha_wan.conf come back,located under /etc/ directory.</p>
  
  <p>I tried to delete it many many times,It is the same result.</p>
  
  <p>What should I do,I want to permanently remove that file.Thanks.</p>