</para>

<para>

Streaming replication and log-shipping standby servers can remain running until

a later step.

Streaming replication and log-shipping standby servers can

remain running until a later step.

</para>

</step>

<step>

<title>Verify standby servers</title>

<para>

If you are upgrading Streaming Replication and Log-Shipping standby

servers, verify that the old standby servers are caught up by running

<application>pg_controldata</> against the old primary and standby

clusters. Verify that the <quote>Latest checkpoint location</>

values match in all clusters. (There will be a mismatch if old

standby servers were shut down before the old primary.)

</para>

</step>

If you have Streaming Replication (<xref

linkend="streaming-replication">) or Log-Shipping (<xref

linkend="warm-standby">) standby servers, follow these steps to

upgrade them (before starting any servers):

upgrade them. You will not be running <application>pg_upgrade</>

on the standby servers, but rather <application>rsync</>. Do not

start any servers yet.

</para>

<substeps>

</para>

</step>

<step>

<title>Verify standby servers</title>

<para>

To prevent old standby servers from being modified, run

<application>pg_controldata</> against the primary and standby

clusters and verify that the <quote>Latest checkpoint location</>

values match in all clusters. (This requires the standbys to be

shut down after the primary.)

</para>

</step>

<step>

<title>Save configuration files</title>