PostgreSQL 12 High Availability Cookbook - Third Edition

How to do it...

The first thing we need to do is to secure the WAL stream. Follow these steps to build a semi-permanent copy of archived WAL data in the /db/wal_archive directory:

1. On the primary node, modify the postgresql.conf file to include the following setting:

archive_command = 'cp -an %p /db/wal_archive/%f'

2. Create the /db/wal_archive directory as a root-capable user using the following commands:

sudo mkdir -p -m 0700 /db/wal_archive
sudo chown -R postgres /db/wal_archive

3. Reload the PostgreSQL service using the following command:

pg_ctl -D /path/to/database reload

4. As a root-capable user, create a script, named del_archives, in the /etc/cron.daily directory and fill it with this content:

find /db/wal_archive -name '0000*' \ -type ...