Backtrack 5 Postgres Database Fix

TL;DR

Your Backtrack 5 R2-64 bit PostgreSQL database isn’t starting? This guide walks you through common causes and fixes, focusing on permissions, configuration files, and service management.

Fixing a Non-Loading Postgres Database in Backtrack 5

1. Check the Service Status
   • First, see if the PostgreSQL service is even running. Open a terminal and type:

     sudo /etc/init.d/postgresql status

   • If it’s not running (shows ‘stopped’), try to start it:

     sudo /etc/init.d/postgresql start

   • Look for any error messages during the startup attempt. These are crucial clues!
2. Examine Log Files
   • PostgreSQL logs errors to a specific file. The location varies, but common places include:
     • /var/log/postgresql
     • /var/log/postgres
     • Check the postgresql.conf file (see step 3) for the exact log path.
   • Use a text editor or command like tail -f /path/to/logfile to view the latest entries in real-time as you attempt to start the service.

     sudo tail -f /var/log/postgresql/postgresql.log

3. Verify Configuration File Permissions
   • The postgresql.conf file needs to be readable by the PostgreSQL user (usually ‘postgres’). Check its permissions:

     ls -l /etc/postgresql/9.1/main/postgresql.conf

     (Replace ‘9.1’ with your Postgres version if different.)

   • If the permissions are incorrect (e.g., owned by root and not readable by postgres), change them:

     sudo chown postgres:postgres /etc/postgresql/9.1/main/postgresql.conf

     sudo chmod 640 /etc/postgresql/9.1/main/postgresql.conf

4. Check Data Directory Permissions
   • The PostgreSQL data directory also needs the correct permissions. Find its location in postgresql.conf (look for the ‘data_directory’ setting).

     grep data_directory /etc/postgresql/9.1/main/postgresql.conf

   • Once you know the path, verify permissions:

     ls -l /var/lib/postgresql/9.1/main

     (Replace ‘9.1’ with your version and adjust the path as needed.)

   • Ensure the ‘postgres’ user owns the directory and has read/write access:

     sudo chown -R postgres:postgres /var/lib/postgresql/9.1/main

     sudo chmod -R 700 /var/lib/postgresql/9.1/main

5. Ensure the Data Directory Exists
   • If the data directory specified in postgresql.conf doesn’t exist, PostgreSQL won’t start.

     ls -l /var/lib/postgresql/9.1/main

   • Create it if necessary:

     sudo mkdir -p /var/lib/postgresql/9.1/main

     (Replace ‘9.1’ with your version and adjust the path as needed.)

6. Restart PostgreSQL
   • After making any changes to permissions or configuration, restart the service:

     sudo /etc/init.d/postgresql restart

   • Check the status again to confirm it’s running.

     sudo /etc/init.d/postgresql status

7. Database Cluster Initialization (If Data Directory Was Empty)
   • If you had to create the data directory, you need to initialize a new database cluster:

     sudo -u postgres initdb -D /var/lib/postgresql/9.1/main

     (Replace ‘9.1’ with your version and adjust the path as needed.)