Migrating a website software version is one of the highest risk procedure a webmaster encounters when managing a website. Drupal 8 Upgrade? Here is a small guide with various details. Let’s start with general info : What the heck is this Drupal thing anyway? OK, so my best understanding of this is that it’s a little software package. It’s written in a language called PHP. It’s made up of core modules which you can download from http://drupal.org/project/drupal, and a bunch of optional (or “contributed”) modules, which you can surf at http://drupal.org/project/modules. All of this then sits around in a little set of folders.
First of all, make a list of all the contributed modules on your current website. Next, check whether these modules have a Drupal 8 compatible version. In case of unavailability of the Drupal 8 version, the migration process will suffer. Fortunately, Drupal 8 has come a long way and many of the major modules now do support Drupal 8. You can check all the available update paths through the Migrate UI modules. When done with the installation of the modules, you will have to navigate to the upgrade path. For this, go to www.yoursite.com/upgrade (remember to replace yoursite with the name of your Drupal 8 website). You will be brought to the following screen. Please make sure you follow the directions on the screen before proceeding.
The upgrade process, and underlying Migration API, are still evolving. We don’t anticipate them changing dramatically even though they are still marked experimental. Beware of any resources that were written before Drupal 8.1.x was released (April 19, 2016) as the system changed considerably in ways that invalidate many of the older articles.
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. Blocks and contexts. Many distributions use the Context module to position blocks. Your existing site may use the core Block module for this purpose, may use Context or some other tool, or may use a combination of tools for block placement. With your new distribution’s blocks displaying as well as those enabled by your existing site, you may get more than you need or want. To address this issue, selectively disable blocks left over from your existing site. If they were custom blocks, you may wish to delete them.
Drupal distributions are usually used as a starting point for developing a new website. The most straightforward way to use a distribution is to install it from scratch. From there, you can selectively migrate in content from other sources, including one or more existing websites. Migrating data here might be as simple as copying and pasting several pages from an old site into the new site. For larger sites, it could involve writing custom migration scripts or using an existing Drupal module like Migrate or Feeds.
There is no easy way around it: upgrading to Drupal 8 is a big change that requires time and attention. To help ease your anxiety around this, we’ve put together a comprehensive overview of the various implications surrounding the upgrade process to Drupal 8, including how to best prepare yourself, your Drupal website, and your team for the project. Read extra info at Migrating from Drupal 7 to Drupal 8.