Re: pg_basebackup --incremental

pgbackrest does WAL archiving for you, as seen here: $ dir /Database/backups/pgbackrest/ total 64 drwxr-x--- 3 nobody nobody 21 2024-06-08 21: 35: 11 archive/ drwxr-x--- 3 nobody nobody 21 2025-06-11 13: 04: 10 backup/ Thus, it obviates the need

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pgbackrest does WAL archiving for you, as seen here:

$ dir /Database/backups/pgbackrest/
total 64
drwxr-x--- 3 nobody nobody 21 2024-06-08 21:35:11 archive/
drwxr-x--- 3 nobody nobody 21 2025-06-11 13:04:10 backup/

Thus, it obviates the need for the rsync commands.

If, like me, you still want the WAL files to also be somewhere else, then create a cron job to rsync {repo1-path}/pgbackrest/archive to <insert destination here> every15 minutes or so. Add "--del" to remove the WALs that pgbackrest deletes when it purges the oldest saveset.

On Wed, Oct 29, 2025 at 2:26 PM Sam Stearns <sam.stearns@dat.com> wrote:

Awesome.  Thank you, Ron.

We have our archive_command set to push WAL's to standby as such:

archive_command = 'test ! -f /postgres_wal_archive/rtsstage/%f && rsync -a %p /postgres_wal_archive/rtsstage/%f && rsync -a %p postgres@10.36.160.48:/postgres_wal_archive/rtsstage/%f'

How does incorporating pgbackrest affect that setup?

On Wed, Oct 29, 2025 at 10:53 AM Ron Johnson <ronljohnsonjr@gmail.com> wrote:

I'm certain this is all in the User Guide: $ grep -rh archive $PGDATA/postgresql. conf* archive_mode = on #archive_command = '/bin/true' archive_command = 'pgbackrest --stanza=nfs archive-push %p' Since changing archive_mode

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I'm certain this is all in the User Guide:

$ grep -rh archive $PGDATA/postgresql.conf*
archive_mode = on
#archive_command = '/bin/true'
archive_command = 'pgbackrest --stanza=nfs archive-push %p'

Since changing archive_mode requires a restart, but changing archive_command just requires a reload, it's useful to have both of those archive_command lines in your config.  Always keep "archive_mode = on" but disable it by setting archive_command to /bin/true (which will be a rare occurrence).

On Wed, Oct 29, 2025 at 1:40 PM Sam Stearns <sam.stearns@dat.com> wrote:

Hi Ron,

If I may, please.  What are the postgres.conf parameters you set specifically for pgBackRest?

Thanks,

Sam

On Tue, Oct 28, 2025 at 3:21 PM Sam Stearns <sam.stearns@dat.com> wrote:

Thanks, Ron!  We'll take another look at pgBackRest.

On Tue, Oct 28, 2025 at 10:52 AM Ron Johnson <ronljohnsonjr@gmail.com> wrote:

On Tue, Oct 28, 2025 at 1: 43 PM Sam Stearns <sam. stearns@ dat. com> wrote: Howdy, We're running version 17. 6. Would anyone be able to point me to, or provide, some sample use cases / scripts / usage to deploy a pg_basebackup full + --incremental

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On Tue, Oct 28, 2025 at 1:43 PM Sam Stearns <sam.stearns@dat.com> wrote:

Howdy,

We're running version 17.6.  Would anyone be able to point me to, or provide, some sample use cases / scripts / usage to deploy a pg_basebackup full + --incremental strategy as a backup solution, please?

The question confuses me a bit (though maybe because weekly "full", and remainder "incremental" is pretty standard).  PgBackRest really is quite simple and easy to configure if you back up to a local mount point (even when that mount point is NFS).

This is in the "postgres" crontab:

15 01 * * Sun Type=full; pgbackrest backup --stanza=nfs --type=$Type &> logs/pgbackrest_$(date +"\%F_\%T")_${Type}.log
15 01 * * 1-6 Type=incr; pgbackrest backup --stanza=nfs --type=$Type &> logs/pgbackrest_$(date +"\%F_\%T")_${Type}.log

And this is my /etc/pgbackrest.conf:

[global]
repo1-path=/Database/backups/pgbackrest
repo1-cipher-type=aes-256-cbc
repo1-cipher-pass=<redacted>
repo1-bundle=y
repo1-bundle-limit=20MiB
repo1-bundle-size=200MiB
[nfs]
pg1-path=/Database/17/data
resume=n
start-fast=y
stop-auto=y
compress-type=zst
log-level-console=detail
log-level-file=info
log-path=/var/lib/pgsql/logs/pgbackrest
retention-full=4
process-max=<nproc * 3/4>
[nfs:archive-push]
compress-type=zst

--

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