What are the first steps you should take when your SQL database won't start?

1 Check Logs

The very first action is to examine the SQL server logs. These files provide a record of all server activities and can offer insights into what caused the failure. To access these logs, use the SQL Server Management Studio (SSMS) or look for the text files in the SQL server's log folder. You're looking for any error messages or unusual entries that occurred just before the database failed to start. Identifying the exact error can significantly narrow down the potential causes and solutions.

2 Verify Services

Next, ensure that the SQL Server service is running. On a Windows server, open the 'Services' app and locate 'SQL Server (instance name)' in the list. If the service isn't running, attempt to start it manually. If it fails to start, the event viewer may provide more details about the error. For a Linux server, you can use the command systemctl status mssql-server to check the service status and systemctl start mssql-server to start it.

3 Inspect Hardware

Hardware issues can prevent a SQL database from starting. Check your server's hardware components, including hard drives, memory, and network connectivity, for any signs of failure or malfunction. If you find hardware problems, you may need to replace or repair the affected components. Remember that hardware malfunctions can cause data corruption, so it's crucial to have recent backups of your database.

4 Review Configuration

If hardware isn't at fault, review the SQL server configuration settings. Incorrect configurations can lead to startup failures. Use SSMS or configuration tools specific to your SQL server to verify that all settings are correct. Pay close attention to file paths, memory allocation, and user permissions, as these are common culprits for startup issues.

5 Database Consistency

Running a database consistency check can help identify and fix database corruption issues. Use the SQL Server's built-in command DBCC CHECKDB to perform this check. If inconsistencies are found, the command will attempt to repair them. However, be cautious as some repair options can lead to data loss. It's always best to work on a backup of your database when performing potentially destructive operations.

6 Contact Support

If all else fails, it's time to reach out for professional help. Contact your database support team or a certified SQL database professional. Provide them with all the information you've gathered, including error logs, hardware check results, and any steps you've already attempted. Their expertise will be invaluable in diagnosing and resolving the issue with minimal data loss and downtime.