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Site Restoration

#43050 Akeeba restore error: Unknown collation utf8mb4_0900_ai_ci when migrating MySQL 8 to MariaDB 10.11

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Environment Information

PHP version
8.4
CMS Type
Joomla!
CMS Version
6
Backup Tool Version
10.3.5
Kickstart version
9.1.0

Latest post by nicholas on Friday, 19 June 2026 07:00 CDT

budspencer
Hello,

I am migrating a Joomla site using Akeeba Backup from the following source server:

Server type: MySQL
Server version: 8.0.19 - MySQL Community Server - GPL
Protocol version: 10
Server charset: UTF-8 Unicode (utf8mb4)

to the following target server:

Server type: MariaDB
Server version: 10.11.14-MariaDB-0ubuntu0.24.04.1 (Ubuntu 24.04)
Protocol version: 10
Server charset: UTF-8 Unicode (utf8mb4)

During the database import/restore process, I receive the following error:

ErrNo #1273
Unknown collation: 'utf8mb4_0900_ai_ci'

(see attached screenshot)

It looks like the dump created on MySQL 8 uses the collation utf8mb4_0900_ai_ci, which is not supported by MariaDB 10.11.

Could you please advise on the best way to handle this migration?
Is there a recommended method within Akeeba to automatically convert or map this collation during restore, or should the SQL dump be modified manually?

Any guidance would be greatly appreciated.

Thank you very much!

nicholas
Akeeba Staff
Manager

You need to enable the "Normalize character set" option in the database restoration page. Kindly note that the help for this feature reads:

Allows BRS to translate the character set explicitly set on a table or a column to what is appropriate for the database server you are restoring to. Enabled by default, and recommended to be left enabled when transferring a site between different database server types (e.g. MySQL to MariaDB, or vice versa), or different database server versions (e.g. MySQL 5.6 to 8.0)

Nicholas K. Dionysopoulos

Lead Developer and Director

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Please keep in mind my timezone and cultural differences when reading my replies. Thank you!

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