diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
new file mode 100644
index b8daedc..737355a
*** a/doc/src/sgml/backup.sgml
--- b/doc/src/sgml/backup.sgml
*************** SELECT pg_stop_backup();
*** 869,875 ****
      of mistakes when restoring.  This is easy to arrange if
      <filename>pg_xlog/</> is a symbolic link pointing to someplace outside
      the cluster directory, which is a common setup anyway for performance
!     reasons.
     </para>
  
     <para>
--- 869,879 ----
      of mistakes when restoring.  This is easy to arrange if
      <filename>pg_xlog/</> is a symbolic link pointing to someplace outside
      the cluster directory, which is a common setup anyway for performance
!     reasons.  You might also want to exclude <filename>postmaster.pid</>
!     and <filename>postmaster.opts</>, which record information
!     about the running <application>postmaster</>, not about the
!     <application>postmaster</> which will eventually use this backup.
!     (These files can confuse <application>pg_ctl</>.)
     </para>
  
     <para>