Date: Fri, 15 Sep 2017 16:17:52 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Andreas Joseph Krogh <andreas@visena.com>
Cc: Michael Paquier <michael.paquier@gmail.com>,
	Robert Haas <robertmhaas@gmail.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
	Stephen Frost <sfrost@snowman.net>
Subject: Re: Clarification in pg10's pgupgrade.html step 10
 (upgrading standby servers)
Message-ID: <20170915201752.GA9874@momjian.us>
References: <20170914191356.GC6595@momjian.us>
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On Fri, Sep 15, 2017 at 01:23:45AM +0200, Andreas Joseph Krogh wrote:
> I tested upgrading from 9.6 to 10 now, using pg_upgrade, and pg_upgrade creates
> the new data-dir with pg_wal "in it" (just like regular initdb), so pg_upgrade
> seems not to care about where the old version's pg_xlog was. You have to move
> (by symlinking) pg_wal to a separate location manually *after* running
> pg_upgrade on the master. No special handling is needed when rsync'ing it over
> to the standby, so it doesn't need any --hard-links or --size-only, correct?

What rsync is going to do is to reproduce the directory structure of the
old cluster _in_ the standby's old cluster, and the structure of the new
cluster on the standby's new cluster.  If you had the WAL directory
relocated in the new cluster, the relocation symbolic link will be
reproduced by rsync, but the directory it points _to_ will not be
copied, so it will point to nothing.

Of course, of both old and new clusters share the same WAL directory,
which I think is impossible, things would get very confusing quickly.  I
will reply to this now in a later email.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +


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