The Problem:

When using XAMPP Control Panel on a Windows environment, users may encounter the following error messages:

[ERROR] mysqld.exe: Table '.\mysql\db' is marked as crashed and last (automatic?) repair failed
[ERROR] Fatal error: Can't open and lock privilege tables: Table '.\mysql\db' is marked as crashed and last (automatic?) repair failed
[ERROR] Aborting

These errors indicate that the MySQL service is unable to start due to a corrupted table in the MySQL database.

Problem Analysis:

The primary symptom of this issue is the failure of the MySQL service to start when initiated from the XAMPP Control Panel. The error messages specify that the db table within the MySQL database is marked as crashed and that an automatic repair attempt has failed. This typically results in the MySQL service aborting the startup process, making the database inaccessible.

Root Cause:

The root cause of this problem is the corruption of the db table within the MySQL database. This corruption can occur due to several reasons, including:

• Unexpected shutdowns or crashes of the MySQL server.
• Disk write errors.
• File system corruption.
• Insufficient disk space.

Solution:

To resolve this issue, follow these steps to manually repair the corrupted MySQL table:

1. Stop the MySQL Service:

   • Open the XAMPP Control Panel.
   • Click the "Stop" button next to the MySQL service to ensure it is not running.

2. Open Command Prompt as Administrator:

   • Press Win + S and type cmd.
   • Right-click on "Command Prompt" and select "Run as administrator".

3. Navigate to the MySQL Directory:

   • In the Command Prompt, navigate to the MySQL bin directory within your XAMPP installation. For example:

     cd C:\xampp\mysql\bin

4. Start MySQL in Safe Mode:

   • Start MySQL with the innodb_force_recovery option to allow access to the corrupted tables:

     mysqld --console --skip-grant-tables --skip-networking --innodb_force_recovery=1

   • This command starts MySQL in a limited mode that prevents it from applying certain recovery operations that could fail due to the corruption.

5. Repair the Corrupted Table:

   • Open another Command Prompt window as Administrator.
   • Navigate to the MySQL bin directory again:

     cd C:\xampp\mysql\bin

   • Connect to the MySQL server using the MySQL command-line client:

     mysql -u root

   • Once connected, select the MySQL database:

     USE mysql;

   • Repair the corrupted db table:

     REPAIR TABLE db;

6. Stop the MySQL Safe Mode:

   • Return to the first Command Prompt window where MySQL was started in safe mode.
   • Press Ctrl + C to stop the MySQL server.

7. Restart MySQL Normally:

   • Go back to the XAMPP Control Panel.
   • Click the "Start" button next to the MySQL service to start it normally.

8. Verify the Fix:

   • Check the XAMPP Control Panel to ensure that the MySQL service is running without errors.
   • Optionally, you can log in to phpMyAdmin to verify that the databases and tables are accessible.

By following these steps, you should be able to resolve the issue of the crashed MySQL table and restore normal operation of the MySQL service in XAMPP.