Update procedure (minor version change)
Updating your Drupal site means taking it from, for example, Drupal 7.43 to 7.50; or from 8.0.0 to 8.1.7. A Drupal 'update' is also referred to as a 'minor' version change.
Note: If you want to take your site from Drupal 6 to Drupal 7 or 8, or from Drupal 7 to Drupal 8, that is referred to as an 'Upgrade'. Go to Upgrade to Drupal 7 or 8 - Major version change to your current Drupal site
First steps and definitions:
- If you are upgrading to Drupal version x.y.z, then x is known as the major version number, y is known as the minor version number, and z is known as the patch version number. The download file will be named drupal-x.y.z.tar.gz (or drupal-x.y.z.zip). Drupal 7 uses only x.y (MAJOR.MINOR) to designate versions.
- All directories mentioned in these documents are relative to the directory of your Drupal installation.
- Make a full backup of all files, directories, and your database(s) before starting, and save it outside your Drupal installation directory. Instructions may be found at http://drupal.org/upgrade/backing-up-the-db
- It is wise to try an update or upgrade on a test copy of your site before applying it to your live site. Even minor updates, can cause your site's behavior to change.
- Each new release of Drupal has release notes, which explain the changes made since the previous version and any special instructions needed to update or upgrade to the new version. You can find a link to the release notes for the version you are upgrading or updating to on the Drupal project page (https://www.drupal.org/project/drupal).
If you encounter errors during this process:
- Note any error messages you see.
- Restore your site to its previous state, using the file and database backups you created before you started the update process. Do not attempt to do further updates on a site that had update problems.
- Consult one of the support options listed on http://drupal.org/support
The standard process of updating is as follows:
- Take backups of all files and database
- Put site in Maintenance Mode (under Configuration / Development)
- Delete all files except the Sites folder and any files such as ".htaccess" and "robots.txt" that have been customized. (This assumes any contributed modules, custom themes etc. That you use are in the sites directory)
- Upload the new files except the sites directory or the .htaccess or .robots.txt files.
- If changes have been made to robots.txt or .htaccess in the new version ensure these are incorporated into your version. The release notes should tell you whether this is required.
- Run Update.php by visiting yourdomain.com/update.php
- While Update.php runs if you got any errors like below use the Module missing message fixer to overcome these errors.(For 7.5x versions only)
The following module is missing from the file system: MODULE NAME. In order to fix this, put the module back in its original location. For more information, see the documentation page.
User warning: The following module is missing from the file system: MODULE NAME. In order to fix this, put the module back in its original location. For more information, see the the documentation page. in _drupal_trigger_error_with_delayed_logging()
- Switch off maintenance mode by reversing step 2
- Take some time to test the site is functioning as expected.
More in-depth information on updating and upgrading can be found at http://drupal.org/upgrade