Oracle Database Upgrade Guide for Ubuntu

1. Pre-Upgrade Preparation

1.1 Verify System Requirements

Ensure your Ubuntu system meets the minimum requirements for the target Oracle Database version (e.g., CPU architecture, memory, disk space). Refer to the official Oracle documentation for version-specific specs.

1.2 Install Required Dependencies

Run the following commands to install essential packages for Oracle installation:

sudo apt update
sudo apt install alien libaio1 unixodbc unzip wget -y

1.3 Backup the Database

Perform a full backup using RMAN (Recovery Manager) to ensure data safety:

rman target /
RUN {
    ALLOCATE CHANNEL c1 DEVICE TYPE DISK;
    BACKUP DATABASE PLUS ARCHIVELOG FORMAT '/u01/backup/%U';
    RELEASE CHANNEL c1;
}

Also, back up critical configuration files (e.g., listener.ora, tnsnames.ora) from $ORACLE_HOME/network/admin.

1.4 Check Compatibility

Confirm your current Oracle version supports a direct upgrade to the target version. For example:

• Oracle 19c/18c/12.2 can upgrade directly to 21c.
• Versions earlier than 12.2 (e.g., 11.2.0.4) require an intermediate upgrade to 12.2 first.
  Use this SQL query to check your current COMPATIBLE parameter:

SELECT name, value FROM v$parameter WHERE name = 'compatible';

Refer to Oracle’s Compatibility Matrix for detailed requirements.

1.5 Modify Kernel Parameters

Adjust Ubuntu kernel parameters to meet Oracle’s requirements. Edit /etc/sysctl.conf and add:

fs.file-max = 6815744
kernel.sem = 250 32000 100 128
net.ipv4.ip_local_port_range = 9000 65500

Apply changes with sudo sysctl -p.

1.6 Update User Limits

Edit /etc/security/limits.conf to increase resource limits for the oracle user:

oracle soft nproc 2047
oracle hard nproc 16384
oracle soft nofile 1024
oracle hard nofile 65536

1.7 Download the Target Oracle Version

Get the Oracle Database installation package from the official website. For Ubuntu, you’ll typically download a .zip or .tar.gz file (RPM packages may require conversion using alien).

2. Install the Target Oracle Version

2.1 Extract the Package

Unzip the downloaded file to a temporary directory:

unzip linux.x64_21c_database.zip -d /u01/app/oracle/product/21.0.0/dbhome_1

2.2 Set Environment Variables

Edit the oracle user’s .bash_profile to include Oracle environment variables:

export ORACLE_HOME=/u01/app/oracle/product/21.0.0/dbhome_1
export ORACLE_SID=orcl
export PATH=$ORACLE_HOME/bin:$PATH
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH

Source the file to apply changes:

source ~/.bash_profile

2.3 Run the Installer (Silent Mode)

Execute the Oracle Universal Installer (OUI) in silent mode to install the software:

sudo /u01/app/oracle/product/21.0.0/dbhome_1/runInstaller -silent -responseFile /u01/app/oracle/product/21.0.0/dbhome_1/response/db_install.rsp \
ORACLE_HOME=/u01/app/oracle/product/21.0.0/dbhome_1 \
ORACLE_BASE=/u01/app/oracle \
oracle.install.option=INSTALL_DB_SWONLY \
UNIX_GROUP_NAME=oinstall \
INVENTORY_LOCATION=/u01/app/oraInventory \
SELECTED_LANGUAGES=en \
ORACLE_HOME_NAME=OraDB21Home1

Complete the installation and run the root scripts when prompted:

sudo /u01/app/oraInventory/orainstRoot.sh
sudo /u01/app/oracle/product/21.0.0/dbhome_1/root.sh

3. Perform the Database Upgrade

3.1 Start the Database in Upgrade Mode

Switch to the oracle user and start the database in UPGRADE mode:

sqlplus / as sysdba
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP UPGRADE;

3.2 Run the Pre-Upgrade Script

Execute the pre-upgrade script to fix compatibility issues:

cd $ORACLE_HOME/rdbms/admin
sqlplus / as sysdba @preupgrade_fixups.sql

3.3 Use DBUA (Optional but Recommended)

For a GUI-based upgrade, run the Database Upgrade Assistant (DBUA):

dbua

Follow the on-screen instructions to complete the upgrade. DBUA automates most steps and provides progress tracking.

3.4 Manual Upgrade (Alternative)

If using DBUA is not feasible, run the upgrade script manually:

sqlplus / as sysdba @catupgrd.sql

This script upgrades the data dictionary and other database components. After completion, run:

sqlplus / as sysdba @utlrp.sql

to recompile invalid objects.

3.5 Update the COMPATIBLE Parameter

After a successful upgrade, modify the COMPATIBLE parameter to the target version (e.g., 21.0.0) to enable new features:

ALTER SYSTEM SET COMPATIBLE = '21.0.0' SCOPE=SPFILE;
SHUTDOWN IMMEDIATE;
STARTUP;

3.6 Finalize the Upgrade

• Recompile invalid objects:

  @utlrp.sql
  

• Check for upgrade errors in the alert log ($ORACLE_BASE/diag/rdbms/<SID>/<SID>/trace/alert_<SID>.log).
• Verify the upgrade:

  SELECT version FROM v$instance;
  

4. Post-Upgrade Tasks

4.1 Back Up the Upgraded Database

Perform a full backup of the upgraded database to protect against data loss:

rman target /
RUN {
    ALLOCATE CHANNEL c1 DEVICE TYPE DISK;
    BACKUP DATABASE PLUS ARCHIVELOG FORMAT '/u01/backup/%U';
    RELEASE CHANNEL c1;
}

4.2 Test Applications

Connect to the database using your applications and run test queries to ensure compatibility. Update connection strings if the ORACLE_SID or ORACLE_HOME has changed.

4.3 Monitor Performance

Use Oracle Enterprise Manager (OEM) or AWR reports to monitor performance. Compare pre- and post-upgrade metrics to identify bottlenecks.

4.4 Clean Up Old Files

Remove temporary files and old Oracle Home directories to free up disk space.

Troubleshooting Tips

• Failed Upgrade: If the upgrade fails, check the alert log for errors. Use flashback database (if enabled) to revert to the pre-upgrade state.
• Missing Dependencies: Install any missing libraries (e.g., libaio) and rerun the upgrade.
• Compatibility Issues: Refer to Oracle’s Pre-Upgrade Checklist to resolve issues before starting.

By following these steps, you can successfully upgrade Oracle Database on Ubuntu while minimizing risks and ensuring data integrity. Always refer to the official Oracle documentation for version-specific details.