Migrating a website software version is one of the most complicated procedure a webmaster has to deal with when managing a website. Migrating from Drupal 7? Here is a small guide with various details. Let’s start with basic info : Be careful where you put your optional modules and themes. Within the folders of your Drupal installation, there is a folder called ‘modules’ and one called ‘themes.’ These are NOT where you should put any contributed modules and themes that you add to your core installation. These folders are just for the core modules and themes. The folders you should use are a second set also called modules and themes, which sit within the ‘sites’ folder in your Drupal installation.
The very first thing you should do is to make a local version of the website. This is an essential step because making changes to a live website is very risky and is never a recommended practice. This way, if anything does go awry, your actual website will remain safe and functional. After proceeding, you will be brought to the Migrate UI where you can check all the potential issues and errors that you might encounter as well as all the available and the missing paths. Go through this screen and when satisfied, start the migration.
Upgrading is the process of moving your site from a previous major version of Drupal to a newer version, for example from Drupal 7 to Drupal 8. This consists of upgrading the codebase to the appropriate version and then migrating the data from your old site into the new one. Drupal 8 core contains two modules to help facilitate this process: Migrate Drupal and Migrate Drupal UI.
The steps above outline how to get a distribution minimally installed on an existing site. But you’ll still have a lot of work to do to reconcile your existing site content and structure with what has been created by the distribution. Here are a few tips to get you started–but you should begin with the assumption that there will be lots more you’ll discover and need to fix. Roles. Many distributions will create one or more custom roles. Examples include contributor, editor, and administrator. If any of these roughly correspond to existing roles on your site, delete the roles created by the distribution and rename the existing ones to use the distribution role names. For example, if your site has a role called “site administrator” and the distribution has created a role called “administrator”, delete the newly created “administrator” role and rename “site administrator” to “administrator”. After adjusting the role names, visit admin/config/people/accounts, ensure the “administrator” role is selected as the “Administrator role”, and save the form. Consolidating the roles in this way will get you the functionality of the distribution’s roles and permissions while maintaining your existing users’ role allocations.
Update your site to the latest version of Drupal 6 (core and contributed modules). Before upgrading to Drupal 7, disable and uninstall modules you know you won’t be using in the new site. To help determine which modules to uninstall, you could review the list of modules included in the distribution, which often are found in the download in the directory profiles/[distribution_name]/modules. If a given module is not in the distribution and you don’t foresee needing its functionality on your new site, you may choose to uninstall it.
There are several tips and best practices to follow to help you prepare for the upgrade. Still, since this is such a complex process, we highly recommend getting members of your development team involved from the beginning, which will help ensure the upgrade goes as smoothly as possible. Upgrading to Drupal 8 is more similar to building a new website than previous Drupal updates were, meaning that you should never perform the upgrade to Drupal 8 on a live site. It’s also strongly recommended that you create a backup of your live site so that if anything goes awry, you can quickly roll the site back to an earlier version while you figure out what the issue is. Read more details about Migrating from Drupal 7 to Drupal 8.