Re: postgres replication without pg_basebackup? postgres 13.3

Dear Laurenz,
Thank you very much for the idea.
We ran pg_rewind correctly:

[postgres(at)gacsdb05 data-13.3]$ pg_rewind -c -R
--target-pgdata=/PostgresDB/sas_hdd/data-13.3/ --source-server="host=XXXX
port=XXXX user=postgres password=XXX"

pg_rewind: source and target cluster are on the same timeline

pg_rewind: no rewind required

but then we got the following error:

[2022-11-07 22:57:55 CET-]LOG: starting PostgreSQL 13.3 on
x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat
8.5.0-10), 64-bit

[2022-11-07 22:57:55 CET-]LOG: listening on IPv4 address "0.0.0.0", port
XXXX

[2022-11-07 22:57:55 CET-]LOG: could not create IPv6 socket for address
"::": Address family not supported by protocol

[2022-11-07 22:57:55 CET-]LOG: listening on Unix socket
"/tmp/.s.PGSQL.XXXX"

[2022-11-07 22:57:55 CET-]LOG: database system was shut down in recovery
at 2022-11-07 22:57:47 CET

[2022-11-07 22:57:55 CET-]LOG: restored log file "00000003.history" from
archive

cp: cannot stat '/PostgresWalLogArchive/new/00000004.history': No such file
or directory

[2022-11-07 22:57:55 CET-]LOG: entering standby mode

[2022-11-07 22:57:55 CET-]LOG: restored log file "00000003.history" from
archive

[2022-11-07 22:57:55 CET-]LOG: invalid primary checkpoint record

[2022-11-07 22:57:55 CET-]PANIC: could not locate a valid checkpoint record

[2022-11-07 22:57:55 CET-]LOG: startup process (PID 3011860) was
terminated by signal 6: Aborted

[2022-11-07 22:57:55 CET-]LOG: aborting startup due to startup process
failure

[2022-11-07 22:57:55 CET-]LOG: database system is shut down

We have read we can run pg_resetwal but the Wal folder is the folder where
the Wals are archived in the primary. Would that be correct to reset them?

Any suggestion?

Thank you so much,

Pilar

El lun, 7 nov 2022 a las 12:21, Laurenz Albe (<laurenz(dot)albe(at)cybertec(dot)at>)
escribió:

> On Mon, 2022-11-07 at 11:02 +0100, Pilar de Teodoro wrote:
> > We have a very large database of 37TB and we had to promote our standby
> to primary due to
> > some disk failures. Now the issues are solved, we would like to make
> standby the old primary
> > from a copy of the new primary which is already in place. Is it
> possible without using pg_basebackup?
>
> That's exactly what "pg_rewind" is for. It is a fast version of
> "pg_basebackup" for exactly
> that case.
>
> Yours,
> Laurenz Albe
> --
> Cybertec | https://www.cybertec-postgresql.com
>