diff --git a/doc/src/sgml/pgupgrade.sgml b/doc/src/sgml/pgupgrade.sgml
new file mode 100644
index cffcebb..fcbe551
*** a/doc/src/sgml/pgupgrade.sgml
--- b/doc/src/sgml/pgupgrade.sgml
*************** psql --username postgres --file script.s
*** 530,536 ****
     of the old cluster, use <command>rsync</> to create a dirty
     copy of the old cluster while the server is running, then shut down
     the old server and run <command>rsync</> again to update the copy with any
!    changes to make it consistent.
    </para>
  
   <refsect2>
--- 530,538 ----
     of the old cluster, use <command>rsync</> to create a dirty
     copy of the old cluster while the server is running, then shut down
     the old server and run <command>rsync</> again to update the copy with any
!    changes to make it consistent.  You might want to exclude some
!    files, e.g. <filename>postmaster.pid</>, as documented in <xref
!    linkend="backup-lowlevel-base-backup">.
    </para>
  
   <refsect2>