Install PostgreSQL 15

Admin Feb 25, 2026 PostgreSQL
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Install and Configure PostgreSQL 15

Table of Contents

  1. Install PostgreSQL 15
  2. Create directories
  3. Change PGDATA directory
  4. Initialize the database
  5. Enable automatic start
  6. Enable archive mode and change archive location
  7. Reload PostgreSQL service
  8. Verify configuration
  9. Add firewall rules

Step 1: Install PostgreSQL 15

# Install the repository RPM:
dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x86_64/pgdg-redhat-repo-latest.noarch.rpm

# Disable the built-in PostgreSQL module:
dnf -qy module disable postgresql

# Install PostgreSQL:
dnf install -y postgresql15-server

Step 2: Create directories

mkdir -p /pgTb/pgsql15/trdda
mkdir -p /pgIx/pgsql15/trdda
mkdir -p /pgBackup/pgsql15/trdda
mkdir -p /pgArch/pgsql15/arch
mkdir -p /pgData/pgsql15/data
mkdir -p /pgWal/pgsql15/wal

chown -R postgres:postgres /pg*
chmod -R 700 /pg*

Step 3: Change PGDATA directory

As root:

[root@lxtrdpgdsgv01 ~]# cat /usr/lib/systemd/system/postgresql-15.service | grep -i "Environment=PGDATA"
Environment=PGDATA=/pgData/pgsql15/data
[root@lxtrdpgdsgv01 ~]#

# systemctl daemon-reload

Step 4: Initialize the database

Run as postgres user:

/usr/pgsql-15/bin/initdb -D /pgData/pgsql15/data --waldir=/pgWal/pgsql15/wal
/usr/pgsql-15/bin/pg_ctl -D /pgData/pgsql15/data -l logfile start
ps -ef | grep postgres
/usr/pgsql-15/bin/pg_ctl -D /pgData/pgsql15/data stop

Step 5: Enable automatic start

systemctl stop postgresql-15
systemctl enable postgresql-15
systemctl start postgresql-15
systemctl status postgresql-15

Step 6: Enable archive mode and change archive location

As postgres user:

cp /pgData/pgsql15/data/postgresql.conf /pgData/pgsql15/data/postgresql.conf.bkp
grep -v '^#' /pgData/pgsql15/data/postgresql.conf.bkp | grep '^[A-Za-z0-9]' > /pgData/pgsql15/data/postgresql.conf

edit -- /pgData/pgsql15/data/postgresql.conf

# Added by DBA
listen_addresses = '0.0.0.0' # ipv4 only
max_wal_senders = 10
max_replication_slots = 10
wal_level = 'replica' # or 'logical'
hot_standby = on
archive_mode = on
archive_command = 'cp %p /pgArch/pgsql17/arch/%f'
# shared_preload_libraries = 'repmgr'
wal_log_hints = on
# End

Step 7: Reload PostgreSQL service

systemctl stop postgresql-15.service
systemctl start postgresql-15.service

Step 8: Verify configuration

sed -i "s/PGDATA=.*/PGDATA=\/pgData\/pgsql15\/data/" .bash_profile

psql

SHOW data_directory;
SHOW archive_mode;
SHOW archive_command;
SHOW archive_timeout;
ls -ld $(psql -t -c "SHOW data_directory")/pg_wal
SELECT pg_switch_wal();
ls -lrth /pgArch/pgsql15/arch/

SELECT f AS wal_file,
       (pg_stat_file('/pgArch/pgsql15/arch/' || f)).size AS size_bytes,
       (pg_stat_file('/pgArch/pgsql15/arch/' || f)).modification AS modified_time
FROM pg_ls_dir('/pgArch/pgsql15/arch') f
WHERE f ~ '^[0-9A-F]{24}$'
ORDER BY modified_time DESC;

Step 9: Add firewall rules

# need sudo or root user 
firewall-cmd --add-port=5432/tcp --permanent --zone=public
firewall-cmd --reload
firewall-cmd --list-ports

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