Oracle Database 19c — Two Independent Instances on Oracle Linux 8

A production-ready guide to installing Oracle Database 19c SE2 with two independent databases, dedicated listeners, ARCHIVELOG, RMAN backup strategy, and systemd auto-start. Built from real deployment experience.

Features

Two independent databases — PROD1 and PROD2 on separate mount points, fully isolated data and FRA
Dedicated listeners — LISTENER_PROD1 on 1521, LISTENER_PROD2 on 15210, each registered independently
ARCHIVELOG mode + FORCE LOGGING — both instances ready for RMAN and standby
Fast Recovery Area — per-database FRA with configurable size
Systemd integration — listeners and databases start/stop automatically on boot via two service units
RMAN backup strategy — incremental level 0 + archivelog backup with obsolete cleanup
Hardened OS — SELinux enforcing, firewalld with only required ports open
Silent install — fully scriptable, no GUI required

Architecture

dbhost1.example.com
│
├── Oracle Home (shared)
│   └── /u01/app/oracle/product/19c/dbhome_1
│
├── PROD1
│   ├── Data:     /u02/oradata/PROD1
│   ├── FRA:      /u02/fra/PROD1
│   └── Listener: LISTENER_PROD1  →  TCP 1521
│
└── PROD2
    ├── Data:     /u03/oradata/PROD2
    ├── FRA:      /u03/fra/PROD2
    └── Listener: LISTENER_PROD2  →  TCP 15210

Why two listeners instead of one?

Approach	Trade-off
Single `LISTENER` on 1521, both DBs registered	Cannot independently stop/start listener per database; harder to isolate connections
Dedicated listener per database	✅ Independent control, cleaner separation, easier firewall rules per service

Repository Structure

oracle19c-two-instances/
├── config/
│   ├── listener.ora              # Dual-listener network config
│   └── tnsnames.ora              # Local TNS aliases for both instances
├── scripts/
│   ├── 01_os_prep.sh             # Hostname, hosts file, DNF packages
│   ├── 02_user_dirs.sh           # Mount points and ownership
│   ├── 03_env_profile.sh         # oracle user bash_profile
│   ├── 04_install_sw.sh          # Silent Oracle software install
│   ├── 05_patch_ru.sh            # OPatch replacement and RU apply
│   ├── 07_create_db.sh           # DBCA silent DB creation (both instances)
│   ├── 08_archivelog.sql         # Enable ARCHIVELOG + FRA (run per instance)
│   ├── 09_systemd_setup.sh       # Install and enable systemd service units
│   ├── 10_firewall.sh            # Firewalld rules
│   └── 11_validate.sh            # Post-install validation
├── rman/
│   └── backup_level0.rman        # RMAN incremental level 0 + archivelog script
├── systemd/
│   ├── oracle-listeners.service  # Systemd unit — both listeners
│   └── oracle-databases.service  # Systemd unit — dbstart / dbshut
└── README.md

Prerequisites

Oracle Linux 8 (minimal install)
Oracle Database 19c software ZIP (LINUX.X64_193000_db_home.zip)
OPatch 12.2.0.1.x or later ZIP
Desired Release Update (RU) patch ZIP
Root or sudo access
/u01, /u02, /u03 mount points available (separate LUNs or partitions recommended)

Step 1 — OS Preparation

sudo hostnamectl set-hostname dbhost1.example.com
echo "192.0.2.10  dbhost1.example.com dbhost1" | sudo tee -a /etc/hosts

sudo dnf update -y
sudo dnf install -y oracle-database-preinstall-19c unzip tar

oracle-database-preinstall-19c automatically:

Creates the oracle user and oinstall/dba groups
Sets kernel parameters (shmall, shmmax, semaphores, etc.)
Configures /etc/security/limits.conf for Oracle

Step 2 — User and Directory Setup

sudo mkdir -p /u01/app/oracle/product/19c/dbhome_1
sudo mkdir -p /u01/app/oraInventory
sudo mkdir -p /u02/oradata/PROD1 /u02/fra/PROD1
sudo mkdir -p /u03/oradata/PROD2 /u03/fra/PROD2
sudo chown -R oracle:oinstall /u01 /u02 /u03
sudo chmod -R 775 /u01 /u02 /u03

Step 3 — Oracle User Environment

Add to /home/oracle/.bash_profile (or run scripts/03_env_profile.sh):

export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/19c/dbhome_1
export ORA_INVENTORY=/u01/app/oraInventory
export PATH=$ORACLE_HOME/bin:$PATH
export ORACLE_HOSTNAME=dbhost1.example.com

source /home/oracle/.bash_profile

Step 4 — Oracle Software Installation

su - oracle

cd $ORACLE_HOME
unzip -oq /path/to/LINUX.X64_193000_db_home.zip

export CV_ASSUME_DISTID=OEL7.6

./runInstaller -ignorePrereq \
               -waitforcompletion \
               -silent \
               -responseFile $ORACLE_HOME/install/response/db_install.rsp \
               oracle.install.option=INSTALL_DB_SWONLY \
               ORACLE_HOSTNAME=${ORACLE_HOSTNAME} \
               UNIX_GROUP_NAME=oinstall \
               INVENTORY_LOCATION=${ORA_INVENTORY} \
               ORACLE_HOME=${ORACLE_HOME} \
               ORACLE_BASE=${ORACLE_BASE} \
               oracle.install.db.InstallEdition=SE2 \
               oracle.install.db.OSDBA_GROUP=dba \
               oracle.install.db.OSBACKUPDBA_GROUP=dba \
               oracle.install.db.OSDGDBA_GROUP=dba \
               oracle.install.db.OSKMDBA_GROUP=dba \
               oracle.install.db.OSRACDBA_GROUP=dba \
               SECURITY_UPDATES_VIA_MYORACLESUPPORT=false \
               DECLINE_SECURITY_UPDATES=true

Run root scripts when prompted:

sudo /u01/app/oraInventory/orainstRoot.sh
sudo $ORACLE_HOME/root.sh

Step 5 — Patch to Supported Release Update

su - oracle

# Replace OPatch
rm -rf $ORACLE_HOME/OPatch
unzip -oq /path/to/p6880880_190000_Linux-x86-64.zip -d $ORACLE_HOME
export PATH=$ORACLE_HOME/OPatch:$PATH

# Apply RU
unzip -oq /path/to/pNNNNNNNN_190000_Linux-x86-64.zip -d /tmp/ru
opatch apply -silent /tmp/ru/NNNNNNNNN

Verify:

opatch lspatches

Step 6 — Listener Configuration

Copy config/listener.ora and config/tnsnames.ora to $ORACLE_HOME/network/admin/ or create them directly:

listener.ora

LISTENER_PROD1 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbhost1.example.com)(PORT = 1521))
    )
  )

LISTENER_PROD2 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = dbhost1.example.com)(PORT = 15210))
    )
  )

tnsnames.ora

PROD1_LOCAL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = dbhost1.example.com)(PORT = 1521))
    (CONNECT_DATA = (SERVICE_NAME = PROD1))
  )

PROD2_LOCAL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = dbhost1.example.com)(PORT = 15210))
    (CONNECT_DATA = (SERVICE_NAME = PROD2))
  )

Start listeners:

lsnrctl start LISTENER_PROD1
lsnrctl start LISTENER_PROD2

Step 7 — Database Creation

PROD1:

su - oracle

dbca -silent -createDatabase \
     -templateName General_Purpose.dbc \
     -gdbname PROD1 -sid PROD1 \
     -datafileDestination /u02/oradata \
     -characterSet AL32UTF8 \
     -sysPassword 'StrongPass_1234' \
     -systemPassword 'StrongPass_1234' \
     -emConfiguration NONE

export ORACLE_SID=PROD1

sqlplus / as sysdba <<'SQL'
ALTER SYSTEM SET local_listener='PROD1_LOCAL' SCOPE=BOTH;
SHUTDOWN IMMEDIATE;
STARTUP;
SQL

lsnrctl status LISTENER_PROD1

PROD2 (repeat with PROD2 parameters):

dbca -silent -createDatabase \
     -templateName General_Purpose.dbc \
     -gdbname PROD2 -sid PROD2 \
     -datafileDestination /u03/oradata \
     -characterSet AL32UTF8 \
     -sysPassword 'StrongPass_1234' \
     -systemPassword 'StrongPass_1234' \
     -emConfiguration NONE

export ORACLE_SID=PROD2

sqlplus / as sysdba <<'SQL'
ALTER SYSTEM SET local_listener='PROD2_LOCAL' SCOPE=BOTH;
SHUTDOWN IMMEDIATE;
STARTUP;
SQL

lsnrctl status LISTENER_PROD2

Step 8 — Enable ARCHIVELOG and FRA

Run for each instance (change ORACLE_SID, path, and size accordingly):

su - oracle
export ORACLE_SID=PROD1

sqlplus / as sysdba <<'SQL'
ALTER SYSTEM SET db_recovery_file_dest_size = 100G SCOPE=BOTH;
ALTER SYSTEM SET db_recovery_file_dest = '/u02/fra/PROD1' SCOPE=BOTH;

SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE OPEN;
ALTER DATABASE FORCE LOGGING;

ARCHIVE LOG LIST;
SHOW PARAMETER db_recovery_file_dest;
SQL

Repeat for PROD2 with /u03/fra/PROD2.

Step 9 — Systemd Integration

Add both databases to /etc/oratab:

PROD1:/u01/app/oracle/product/19c/dbhome_1:Y
PROD2:/u01/app/oracle/product/19c/dbhome_1:Y

Copy service units from systemd/ or install them directly:

sudo cp systemd/oracle-listeners.service /etc/systemd/system/
sudo cp systemd/oracle-databases.service /etc/systemd/system/

sudo systemctl daemon-reload
sudo systemctl enable oracle-listeners.service oracle-databases.service
sudo systemctl start oracle-listeners.service oracle-databases.service
sudo systemctl status oracle-listeners.service oracle-databases.service

Step 10 — Firewall Configuration

sudo firewall-cmd --permanent --add-port=1521/tcp
sudo firewall-cmd --permanent --add-port=15210/tcp
sudo firewall-cmd --reload
sudo firewall-cmd --list-ports
# → 1521/tcp 15210/tcp

Step 11 — Validation

su - oracle

lsnrctl status LISTENER_PROD1
lsnrctl status LISTENER_PROD2

tnsping PROD1_LOCAL
tnsping PROD2_LOCAL

export ORACLE_SID=PROD1
sqlplus / as sysdba <<'SQL'
SELECT name, open_mode, log_mode FROM v$database;
SQL

export ORACLE_SID=PROD2
sqlplus / as sysdba <<'SQL'
SELECT name, open_mode, log_mode FROM v$database;
SQL

Expected output for each database:

NAME    OPEN_MODE            LOG_MODE
------- -------------------- ------------
PROD1   READ WRITE           ARCHIVELOG

Step 12 — RMAN Backup Strategy

Use rman/backup_level0.rman or run directly:

su - oracle
export ORACLE_SID=PROD1

rman target / <<'EOF'
RUN {
  CONFIGURE CONTROLFILE AUTOBACKUP ON;
  CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;
  BACKUP INCREMENTAL LEVEL 0 DATABASE PLUS ARCHIVELOG;
  DELETE NOPROMPT OBSOLETE;
}
EOF

Repeat for PROD2. Schedule via cron:

# Crontab entry for oracle user — level 0 every Sunday at 01:00
0 1 * * 0 ORACLE_SID=PROD1 $ORACLE_HOME/bin/rman target / @/home/oracle/rman/backup_level0.rman >> /home/oracle/rman/logs/PROD1_$(date +\%F).log 2>&1
0 2 * * 0 ORACLE_SID=PROD2 $ORACLE_HOME/bin/rman target / @/home/oracle/rman/backup_level0.rman >> /home/oracle/rman/logs/PROD2_$(date +\%F).log 2>&1

Step 13 — Hardening & Operations Checklist

SELinux set to enforcing — verify with getenforce
Firewalld active with only ports 1521 and 15210 open
ARCHIVELOG mode confirmed on both instances
RMAN backups scheduled and tested
Release Updates applied quarterly
SYS and SYSTEM passwords changed from defaults
Listener passwords set if required by policy
oratab entries set to Y for both instances (enables dbstart/dbshut)
Systemd services enabled: oracle-listeners and oracle-databases

Troubleshooting

Listener not starting

# Check listener log
cat $ORACLE_BASE/diag/tnslsnr/$(hostname)/listener_prod1/alert/log.xml | tail -50

# Verify port not in use
ss -tlnp | grep -E '1521|15210'

# Try manual start with debug
lsnrctl start LISTENER_PROD1
lsnrctl status LISTENER_PROD1

Database not registering with listener

# Verify local_listener parameter
sqlplus / as sysdba <<'SQL'
SHOW PARAMETER local_listener;
-- Should show PROD1_LOCAL or PROD2_LOCAL
ALTER SYSTEM REGISTER;
SQL

lsnrctl status LISTENER_PROD1
# Service "PROD1" should appear

Systemd service fails to start

journalctl -u oracle-databases.service -n 50

# Verify oratab entries
grep -E 'PROD1|PROD2' /etc/oratab
# Both lines must end with :Y

# Test dbstart manually as oracle user
$ORACLE_HOME/bin/dbstart $ORACLE_HOME

ARCHIVELOG destination filling up

export ORACLE_SID=PROD1
rman target / <<'EOF'
CROSSCHECK ARCHIVELOG ALL;
DELETE NOPROMPT ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-2';
EOF

# Check FRA usage
sqlplus / as sysdba <<'SQL'
SELECT * FROM v$recovery_area_usage;
SQL

Security Notes

Change default passwords — SYS and SYSTEM use placeholder passwords in this guide; replace before going live
Dedicated OS mount points — separate /u02 and /u03 prevent one database from consuming all disk space
SELinux enforcing — do not disable; Oracle 19c runs correctly with enforcing mode on Oracle Linux 8
Minimal firewall exposure — only listener ports are open; no EM Express, no HTTP/HTTPS unless required
Listener without EXTPROC — the listener config in this guide does not expose external procedure calls

License

MIT — free to use, modify, and distribute.

Author

Przemysław Pradela

Built through real production deployment on Oracle Linux 8.

Contributions and issue reports welcome.

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Repository files navigation

Oracle Database 19c — Two Independent Instances on Oracle Linux 8

Features

Architecture

Why two listeners instead of one?

Repository Structure

Prerequisites

Step 1 — OS Preparation

Step 2 — User and Directory Setup

Step 3 — Oracle User Environment

Step 4 — Oracle Software Installation

Step 5 — Patch to Supported Release Update

Step 6 — Listener Configuration

Step 7 — Database Creation

Step 8 — Enable ARCHIVELOG and FRA

Step 9 — Systemd Integration

Step 10 — Firewall Configuration

Step 11 — Validation

Step 12 — RMAN Backup Strategy

Step 13 — Hardening & Operations Checklist

Troubleshooting

Listener not starting

Database not registering with listener

Systemd service fails to start

ARCHIVELOG destination filling up

Security Notes

License

Author

About

Releases

Packages

Contributors

Languages

Name		Name	Last commit message	Last commit date
Latest commit History 12 Commits
config		config
rman		rman
scripts		scripts
systemd		systemd
LICENSE		LICENSE
README.md		README.md

Folders and files

Latest commit

History

Repository files navigation

Oracle Database 19c — Two Independent Instances on Oracle Linux 8

Features

Architecture

Why two listeners instead of one?

Repository Structure

Prerequisites

Step 1 — OS Preparation

Step 2 — User and Directory Setup

Step 3 — Oracle User Environment

Step 4 — Oracle Software Installation

Step 5 — Patch to Supported Release Update

Step 6 — Listener Configuration

Step 7 — Database Creation

Step 8 — Enable ARCHIVELOG and FRA

Step 9 — Systemd Integration

Step 10 — Firewall Configuration

Step 11 — Validation

Step 12 — RMAN Backup Strategy

Step 13 — Hardening & Operations Checklist

Troubleshooting

Listener not starting

Database not registering with listener

Systemd service fails to start

ARCHIVELOG destination filling up

Security Notes

License

Author

About

Topics

Resources

Stars

Watchers

Forks

Releases

Packages

Contributors

Languages