Backdrop CMS includes an update utility to handle any necessary changes to the database schema or configuration. Typically after replacing an older version of a module with a newer one, or the Backdrop core directory, you'll need to check if any updates need to be run.
About minor and major version updates
Backdrop CMS follows a semantic versioning scheme.
- An Update is moving to the next minor (e.g. 1.1.y to 1.2.y) or patch version (e.g. 1.1.1 to 1.1.2).
- An Upgrade is moving the next major version (e.g. from 1.x.y to 2.x.y) and is a more involved process.
Minor and patch version updates maintain consistent APIs, and can be done independently from any additional modules you may have installed on your site. Major version upgrades involve API changes, which will usually at the same time require that all the modules on your site are upgraded to compatible versions.
Minor and patch updates are straight-forward, and usually may be done independently of any module updates. It's usually a good idea to update Backdrop CMS core independently, before attempting any module updates.
- Make a backup of your database.
- Make a backup of the config directory (it's located within the 'files' directory and begins with 'config_` unless otherwise specified in the settings.php file).
- Download the latest release of Backdrop CMS and extract it.
- Login to your site as a user with the "Administrator" role.
- Put your site into maintenance mode (optional, but strongly recommended)
- Rename the core directory in the root directory of your current codebase "core-old" or similar, and move it outside your Backdrop docroot.
- Put the new core directory from the latest release of Backdrop CMS inside your docroot.
- Note: If any of the files outside the core directory have been changed and need to also be updated, they will be explicitly mentioned in the release notes.
- Run update.php by navigating to http://example.com/core/update.php
- If you turned on the maintenance mode option, turn it back off, to make your site publicly accessible again.
- If all is well, delete the "core-old" directory.
Backdrop currently does not have any new major releases (e.g. a Backdrop 2.0), but the process will be the same for future releases as the current process for upgrading from Drupal 7.