MIME-Version: 1.0
References: <CAKoxK+5ypkP1Ts1KNuCgqAxwp=8ejQ-wfiBrpvZ1coZ3dZfOWg@mail.gmail.com>
 <a008ba3a3dab42ea0f7f3d47ad3f3304c5f3eeba.camel@cybertec.at> <CAKoxK+5XT5bAV+w-4dC=rP+a7t2zkvRf8+-wj087yd1Fd5b2iQ@mail.gmail.com>
In-Reply-To: <CAKoxK+5XT5bAV+w-4dC=rP+a7t2zkvRf8+-wj087yd1Fd5b2iQ@mail.gmail.com>
From: Luca Ferrari <fluca1978@gmail.com>
Date: Thu, 8 May 2025 13:26:03 +0200
Message-ID: <CAKoxK+6zvRRBcrqUcHOJ+PwBrc7oGD77cKT6Gmwgvh7F9toswg@mail.gmail.com>
Subject: Re: pg_rewind problem: cannot find WAL
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: pgsql-general <pgsql-general@lists.postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://www.postgresql.org/message-id/CAKoxK%2B6zvRRBcrqUcHOJ%2BPwBrc7oGD77cKT6Gmwgvh7F9toswg%40mail.gmail.com>
Precedence: bulk

On Thu, May 8, 2025 at 8:54=E2=80=AFAM Luca Ferrari <fluca1978@gmail.com> w=
rote:
>
> I've pgbackrest making backups, so I have an archive_command. I'm
> going to see if putting a restore_command can fix the problem.
>

But I'm facing a quite trivial problem: in ubuntu installation the
configuration files are separated from the PGDATA.
Apparently pg_rewind is trying to read postgresql.conf to get the
restore_command, and I don't know how to specify the different
location of the postgresql.conf (cannot specifcy -c as in postgres):

$ /usr/lib/postgresql/17/bin/pg_rewind -D /var/lib/postgresql/17/main
--source-server=3D"user=3Dreplica_fluca host=3Ddev-psqlha3
dbname=3Dreplica_fluca" -R -P --debug -c
postgres: could not access the server configuration file
"/var/lib/postgresql/17/main/postgresql.conf": No such file or
directory
no data was returned by command "/usr/lib/postgresql/17/bin/postgres
-D /var/lib/postgresql/17/main -C restore_command"
child process exited with exit code 2
pg_rewind: error: could not read restore_command from target cluster

Any idea?
Clearly, postgresql.auto.conf is within PGDATA, and since my
recovery_command is there, one trick could be to touch and empty
PGDATA/postgresql.conf, pg_rewind, remove the fake configurtion file.
But I'm sure there is a smarter solution.

Thanks,
Luca