How to recover MySQL database after component_reference_cache.dll error in Laragon

General
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I’m experiencing an issue where I can’t access my MySQL database in Laragon due to a DLL error, but my main concern is recovering the database data. When trying to start MySQL, I get this error:

Service MySQL can not start. Reason: mysqld: Can’t open shared library ‘C:\laragon\bin\mysql\m…\component_reference_cache.dll’ (errno: 126 The specified module could not be found.)

System Configuration:

  • Windows 10
  • Laragon 5.0.0
  • MySQL 8.0.30
  • Database Location: C:\laragon\data\mysql-8\cashier_db\

The database contains critical business data that I need to recover. While fixing the MySQL service would be nice, my priority is safely recovering the data from my existing database files.

I’ve tried several approaches to recover the data:

  1. First Attempt:
  • Action: Copied all database files from backup folder to a new MySQL data directory
  • Expected: Database would be accessible with all data intact
  • Result: MySQL service wouldn’t start, getting errors about duplicate tablespace IDs
  1. Second Attempt:
  • Action: Initialized new MySQL instance and copied only the specific database folder
  • Expected: Clean MySQL installation with restored database
  • Result: Same component_reference_cache.dll error
  1. Third Attempt:
  • Action: Tried to move only the .ibd files from the old database
  • Expected: Database structure with data would be recovered
  • Result: MySQL fails to start when including ibdata1 file

Current Situation:

  • Have complete backup of original database files in mysql-8.bak
  • All .ibd files for ‘cashier_db’ are preserved
  • Original ibdata1 file is available
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Steps to Recover Database Data

1. Backup Everything

Before making any changes, ensure you have a copy of the entire C:\laragon\data\mysql-8.bak folder. This will act as your safety net if anything goes wrong.

2. Install a Clean MySQL Instance

To avoid issues caused by your current MySQL installation, set up a clean environment:

  1. Download MySQL Server:
  • Download the same version of MySQL (8.0.30) from the official website.
  • Install it on your system or another system.
  1. Initialize the Database:
  • Run mysqld --initialize to create a fresh data directory.
  1. Start MySQL Service:
  • Ensure the service starts without errors. Use mysqld directly or through your preferred tool.

3. Prepare Your Old Database Files

To safely import your old database files, follow these steps:

  1. Locate the Required Files:
  • .ibd files: These contain your table data.
  • ibdata1: This file contains metadata for your InnoDB tables.
  1. Check Table Compatibility: Ensure the cashier_db tables are fully compatible with MySQL 8.0.30. Otherwise, you may face issues due to differences in schema versions or table structures.

4. Import the Data Using a New MySQL Instance

Follow the steps below to recover the database:

  1. Stop the MySQL Service: Stop the MySQL service on your new instance to allow manual manipulation of the data directory.
  2. Copy the Database Folder:
  • Copy the cashier_db folder (containing .ibd files) from your backup to the new instance’s data directory.
  • Do not copy ibdata1 yet.
  1. Add Metadata Files: If you have .frm files for your tables, ensure they are also placed in the cashier_db folder.
  2. Edit my.ini: Add the following line to your my.ini configuration file to avoid duplicate tablespace ID errors:

ini

Copy code

innodb_force_recovery = 1

This allows MySQL to start in recovery mode.
5. Start the MySQL Service:

  • Start the service and check if it runs without errors.
  • If it starts, use the MySQL client or any GUI tool (e.g., phpMyAdmin) to export the cashier_db database to a .sql file.
  1. Restore the Exported Data:
  • Stop the MySQL service.
  • Remove any recovery settings (innodb_force_recovery) from my.ini.
  • Start MySQL and import the .sql file into a clean instance.

5. Use Percona Tools for Recovery

If the above method fails, you can use Percona Data Recovery Tools to extract data directly from .ibd files. Here’s how:

  1. Download Percona Tools:
  • Install the Percona Toolkit, which includes utilities for recovering MySQL data.
  1. Recover Data:
  • Use innodb_space to inspect .ibd files and extract table data.
  • Alternatively, ibdconnect can connect .ibd files to a new MySQL instance without relying on ibdata1.

6. Troubleshooting Common Errors

  • Duplicate Tablespace IDs: Ensure you don’t mix ibdata1 files between instances.
  • DLL Errors: If the issue persists on your Laragon setup, repair or reinstall the environment.

Key Tips

  1. Use the same MySQL version (8.0.30) for maximum compatibility.
  2. Always test recovery on a separate environment to avoid overwriting files.
  3. Export recovered data to .sql files to avoid dependency on physical files (ibdata1 or .ibd).

By following the steps above, you should be able to safely recover your critical data. Let me know if you encounter any specific issues during the recovery process!