pg_upgrade: document link options

Document that tablespaces and pg_xlog can be on different file systems
for pg_upgrade --link mode.
Backpatch to 9.3.

diff --git a/doc/src/sgml/pgupgrade.sgml b/doc/src/sgml/pgupgrade.sgml
index d3e26eec1d980529e7531ea12350153aa906eca1..ebb7a60de77c3f71de21531e845f4d0c1d987103 100644 (file)
--- a/doc/src/sgml/pgupgrade.sgml
+++ b/doc/src/sgml/pgupgrade.sgml
@@ -335,7 +335,8 @@ NET STOP pgsql-8.3  (<productname>PostgreSQL</> 8.3 and older used a different s
      copying), but you will not be able to access your old cluster
      once you start the new cluster after the upgrade.  Link mode also
      requires that the old and new cluster data directories be in the
-     same file system.  See <literal>pg_upgrade --help</> for a full
+     same file system.  (Tablespaces and <filename>pg_xlog</> can be on
+     different file systems.)  See <literal>pg_upgrade --help</> for a full
      list of options.
     </para>