Missing or corrupted system tables

Oct 13, 2025 by wbrum.org 14 views

MariaDB 11 Fails to Start: [ERROR] [FATAL] InnoDB: Unable to Find Charset-Collation for 15

MariaDB 11 is a popular open-source relational database management system that offers a robust and scalable solution for managing large amounts of data. However, when upgrading from MariaDB 10.11 to 11.0.1, users may encounter issues with the database failing to start. In this article, we will explore the common causes of this error and provide step-by-step solutions to resolve the issue.

The error message [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 indicates that the InnoDB storage engine is unable to find a valid charset-collation for the specified value (15). This error can occur due to various reasons, including:

Incompatible charset-collation: The charset-collation used in the previous version of MariaDB may not be compatible with the new version.
Missing or corrupted system tables: System tables may be missing or corrupted, causing the InnoDB storage engine to fail.
Incorrect datadir configuration: The datadir configuration may be set to an incorrect location, causing the database to fail to start.

To resolve the issue, follow these step-by-step troubleshooting steps:

Step 1: Verify Datadir Configuration

The datadir configuration specifies the location of the database files. Verify that the datadir configuration is set to the correct location.

mysql -u root -p -e "SHOW VARIABLES LIKE 'datadir';"

If the datadir configuration is set to an incorrect location, update the configuration to point to the correct location.

sudo mkdir -p /var/lib/mysql
sudo chown mysql:mysql /var/lib/mysql

Step 2: Check System Tables

System tables may be missing or corrupted, causing the InnoDB storage engine to fail. Check the system tables for any errors or inconsistencies.

mysql -u root -p -e "SHOW TABLES FROM mysql;"

If any system tables are missing or corrupted, restore them from a backup or recreate them using the mysql_install_db command.

sudo mysql_install_db --user=mysql --datadir=/var/lib/mysql

Step 3: Verify Charset-Collation

The charset-collation used in the previous version of MariaDB may not be compatible with the new version. Verify the charset-collation used in the previous version and update it to a compatible value.

mysql -u root -p -e "SHOW VARIABLES LIKE 'collation_database';"

Update the charset-collation to a compatible value, such as utf8mb4_unicode_ci.

mysql -u root -p -e "SET GLOBAL collation_database = 'utf8mb4_unicode_ci';"

Step 4: Restart MariaDB Service

After verifying the datadir configuration, checking system tables, and verifying the charset-collation, restart the MariaDB service to apply the changes.

sudo systemctl restart mariadb

In this article, we explored the common causes of the [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 error when upgrading from MariaDB 10.11 to 11.0.1. We provided step-by-step troubleshooting steps to resolve the issue, including verifying the datadir configuration, checking system tables, verifying the charset-collation, and restarting the MariaDB service. By following these steps, users can resolve the issue and successfully start their MariaDB 11 database.

For further assistance, refer to the following resources:

MariaDB Documentation: https://mariadb.com/kb/en/
MariaDB Community Forum: https://mariadb.com/community/
AlmaLinux Documentation: https://almalinux.org/docs/

Q: What is the cause of the [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 error?

A: The error is caused by an incompatible charset-collation, missing or corrupted system tables, or incorrect datadir configuration.

Q: How do I resolve the issue?

A: Follow the step-by-step troubleshooting steps outlined in this article, including verifying the datadir configuration, checking system tables, verifying the charset-collation, and restarting the MariaDB service.

Q: What are the consequences of not resolving the issue?

A: If the issue is not resolved, the MariaDB database will fail to start, causing data loss and potential system instability.
MariaDB 11 Fails to Start: [ERROR] [FATAL] InnoDB: Unable to Find Charset-Collation for 15 - Q&A

In our previous article, we explored the common causes of the [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 error when upgrading from MariaDB 10.11 to 11.0.1. We provided step-by-step troubleshooting steps to resolve the issue, including verifying the datadir configuration, checking system tables, verifying the charset-collation, and restarting the MariaDB service. In this Q&A article, we will answer some of the frequently asked questions related to this error.

Q: What is the cause of the [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 error?

A: The error is caused by an incompatible charset-collation, missing or corrupted system tables, or incorrect datadir configuration.

Q: How do I resolve the issue?

A: Follow the step-by-step troubleshooting steps outlined in our previous article, including verifying the datadir configuration, checking system tables, verifying the charset-collation, and restarting the MariaDB service.

Q: What are the consequences of not resolving the issue?

A: If the issue is not resolved, the MariaDB database will fail to start, causing data loss and potential system instability.

Q: Can I use the same charset-collation as in MariaDB 10.11?

A: No, the charset-collation used in MariaDB 10.11 may not be compatible with MariaDB 11. You need to update the charset-collation to a compatible value, such as utf8mb4_unicode_ci.

Q: How do I update the charset-collation?

A: You can update the charset-collation using the following command:

mysql -u root -p -e "SET GLOBAL collation_database = 'utf8mb4_unicode_ci';"

Q: What if I have multiple databases with different charset-collations?

A: In this case, you need to update the charset-collation for each database separately. You can use the following command to update the charset-collation for a specific database:

mysql -u root -p -e "USE database_name; SET GLOBAL collation_database = 'utf8mb4_unicode_ci';"

Q: Can I use a different storage engine instead of InnoDB?

A: Yes, you can use a different storage engine, such as MyISAM or Memory. However, keep in mind that InnoDB is the default storage engine in MariaDB 11, and using a different storage engine may require additional configuration.

Q: How do I configure the storage engine?

A: You can configure the storage engine using the following command:

mysql -u root -p -e "SET GLOBAL default_storage_engine = 'storage_engine_name';"

Q: What if I have a large database with many tables?

A: In this case, you may need to use a different approach to resolve the issue. You can try the following:

Split the database into smaller databases: If you have a large database with many tables, you can try splitting it into smaller databases. This may help you resolve the issue.
Use a different charset-collation: You can try using a different charset-collation that is compatible with MariaDB 11.
Recreate the database: If all else fails, you can try recreating the database from scratch.

In this Q&A article, we answered some of the frequently asked questions related to the [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 error. We provided step-by-step troubleshooting steps and configuration options to help you resolve the issue. If you have any further questions or concerns, please don't hesitate to reach out.

For further assistance, refer to the following resources:

MariaDB Documentation: https://mariadb.com/kb/en/
MariaDB Community Forum: https://mariadb.com/community/
AlmaLinux Documentation: https://almalinux.org/docs/

Q: What is the cause of the [ERROR] [FATAL] InnoDB: Unable to find charset-collation for 15 error?

A: The error is caused by an incompatible charset-collation, missing or corrupted system tables, or incorrect datadir configuration.

Q: How do I resolve the issue?

Q: What are the consequences of not resolving the issue?

A: If the issue is not resolved, the MariaDB database will fail to start, causing data loss and potential system instability.