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Last Reviewed: December 13, 2022


Get your site ready for migration.

Complete the following tasks on the source site to ensure a successful migration.

  1. Check your plugins and/or modules against Modules and Plugins with Known Issues.

  2. Make sure your code is compatible with the latest recommended version of PHP for your CMS. If not, be prepared to adjust PHP versions.

  3. Clear all caches.

  4. Remove unneeded code, database tables, and files.

  5. Configure SSH keys.

  1. Choose to either move the contents of Aquia's nested directory docroot up and remove the folder, or rename the folder to web and set web_docroot: true in your pantheon.yml file. For more information on nested docroots, see Serving Sites from the Web Subdirectory.

  2. Navigate to your Acquia dashboard > click Manage > click Extend. Click Uninstall to uninstall Acquia-specific modules.

  3. Adjust any special Acquia configurations related to env to ensure compatibility with Pantheon's platform.

  4. Uninstall any Acquia Search modules and the default Drupal core Search module (if still enabled for your site) by navigating to admin/modules/uninstall if you plan on using Pantheon Search.


If query cache is turned on within the MySQL service (an obsolete setting), you may notice a severe performance drop on Pantheon during the User Acceptance Testing stage of an active migration from Acquia. We recommend that you move to a modern service to avoid this issue.

If you would like to confirm that your performance drop is caused by the obsolete query cache MySQL service setting, connect to the MySQL service in Acquia’s production environment and run the following:

SHOW VARIABLES LIKE 'query_cache_%';

High values for the query_cache_limit and query_cache_size variables will confirm that performance degradation is related to the MySQL query cache service setting.