Ubuntu Informix Database Management Guide

This guide provides a structured approach to installing, configuring, and managing IBM Informix Dynamic Server (IDS) on Ubuntu, covering essential steps from environment setup to routine administration tasks.

1. Pre-Installation Preparation

Before installing Informix, ensure your Ubuntu system meets the following requirements:

• OS Compatibility: Verify the Informix version supports your Ubuntu release (e.g., Ubuntu 22.04 LTS is commonly supported).
• Dependencies: Install required packages for the installation process:

  sudo apt update && sudo apt install -y build-essential libpcre3 libpcre3-dev zlib1g zlib1g-dev libssl-dev libgd-dev libxml2 libxml2-dev
  

• User/Group Setup: Create a dedicated informix user and group to own Informix files:

  sudo groupadd -g 3000 informix
  sudo useradd -u 3000 -g 3000 -d /opt/informix -m -s /bin/bash informix
  sudo passwd informix  # Set a strong password
  

2. Installing Informix

1. Download the Installer: Obtain the Informix Linux package from IBM’s official website (ensure compatibility with Ubuntu). For example, download informix-11.50.UC4E.Linux-x86-64.tar.gz.
2. Extract and Install:

   sudo mkdir -p /opt/informix
   sudo chown informix:informix /opt/informix
   sudo -u informix tar xzf informix-*.tar.gz -C /opt/informix
   sudo -u informix /opt/informix/ids_install
   

   Follow the on-screen prompts to complete the installation. Default installation paths (e.g., /opt/informix) are recommended.

3. Configuring Environment Variables

Set up environment variables for the informix user to access Informix tools and scripts:

sudo -u informix vi /home/informix/.bash_profile

Add the following lines (adjust paths as needed):

export INFORMIXDIR=/opt/informix
export INFORMIXSERVER=informix_server  # Unique server name (matches onconfig)
export ONCONFIG=onconfig.$INFORMIXSERVER  # Configuration file name
export PATH=$INFORMIXDIR/bin:$PATH
export LD_LIBRARY_PATH=$INFORMIXDIR/lib:$LD_LIBRARY_PATH

Apply changes:

sudo -u informix source /home/informix/.bash_profile

4. Configuring Informix Server

4.1. Create Essential Directories

Informix requires directories for data storage and configuration:

sudo -u informix mkdir -p /opt/informix/data
sudo -u informix touch /opt/informix/data/rootdbs  # Primary dbspace
sudo chown -R informix:informix /opt/informix/data
sudo chmod 660 /opt/informix/data/rootdbs

4.2. Modify onconfig File

Copy the default configuration file and edit critical parameters:

sudo -u informix cp $INFORMIXDIR/etc/onconfig.std $INFORMIXDIR/etc/onconfig.$INFORMIXSERVER
sudo -u informix vi $INFORMIXDIR/etc/onconfig.$INFORMIXSERVER

Key parameters to update:

• ROOTNAME: Name of the root dbspace (e.g., rootdbs).
• ROOTPATH: Path to the root dbspace file (e.g., /opt/informix/data/rootdbs).
• ROOTSIZE: Initial size of the root dbspace (e.g., 30000 pages).
• DBSERVERNAME: Must match INFORMIXSERVER (e.g., informix_server).

4.3. Configure Network Access

Edit the sqlhosts file to define connection protocols:

sudo -u informix vi $INFORMIXDIR/etc/sqlhosts

Add an entry for TCP/IP connections (adjust hostname/IP as needed):

informix_server onsoctcp localhost 9088  # Use 'onsoctcp' for TCP/IP

Update /etc/services to include the Informix service port:

echo "informix_server 9088/tcp" | sudo tee -a /etc/services

5. Starting and Managing the Database Server

5.1. Initialize the Server

Stop any running processes and initialize the server:

sudo -u informix onmode -ky  # Kill all Informix processes
sudo -u informix oninit -iv  # Initialize (creates rootdbs and starts server)

5.2. Verify Server Status

Check server health and configuration:

sudo -u informix onstat -i  # Server initialization status
sudo -u informix onstat -  # General server status

5.3. Stop the Server

Gracefully shut down the server:

sudo -u informix onmode -ky

6. Routine Database Management Tasks

6.1. Connect to the Database

Use dbaccess (command-line tool) to interact with databases:

dbaccess informix -  # Connect to the default 'informix' database

Enter SQL commands (e.g., SELECT * FROM systables;) or exit with .quit.

6.2. Create Databases and Tables

Create a database with a specific dbspace:

CREATE DATABASE mydb IN DBSPACENAME=rootdbs;

Connect to the new database and create a table:

USE mydb;
CREATE TABLE employees (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    salary DECIMAL(10,2)
);

6.3. Backup and Restore

Use dbexport/dbimport for logical backups:

# Backup
dbexport mydb -ss  # Export to 'mydb.exp' directory
# Restore
dbimport mydb -i /path/to/mydb.exp

For physical backups, use ontape (configure in onconfig).

6.4. Monitor Performance

Use onstat to monitor key metrics:

sudo -u informix onstat -g seg  # Disk space usage
sudo -u informix onstat -g cpu  # CPU utilization
sudo -u informix onstat -g ses  # Active sessions

7. Security Best Practices

• File Permissions: Ensure Informix directories (/opt/informix, /opt/informix/data) are owned by informix:informix with 660 permissions for data files.
• Firewall: Restrict access to Informix ports (e.g., 9088/tcp) using ufw:

  sudo ufw allow from 192.168.1.0/24 to any port 9088 proto tcp
  sudo ufw enable
  

• Passwords: Enforce strong passwords for Informix users (use ALTER USER to update).
• Updates: Regularly check for Informix patches and Ubuntu security updates.

Troubleshooting Common Issues

• Permission Denied: Verify informix user ownership of directories and correct permissions.
• Port Conflicts: Ensure no other service uses the Informix port (check with netstat -tulnp | grep 9088).
• Server Fails to Start: Check onstat - output for errors and review $INFORMIXDIR/logs for details.

This guide provides a foundational workflow for managing Informix on Ubuntu. For advanced configurations (e.g., replication, high availability), refer to IBM’s official documentation.