Keep a checked inventory before choosing the migration path.

Identify the actual build.

List core, contributed extensions, themes, custom code and hosting. Note which components provide important behavior and who can verify them.

The official Drupal upgrade documentation separates major-version upgrades from minor and patch updates and provides version-specific preparation paths. Use the guidance that matches the real source and target.

Map content and relationships.

Inventory content types, fields, taxonomy, references, files and translations where used. In a fictional article migration, verify its author, category and attached file as well as the article text.

Protect the editor's work.

Record roles, review steps and the current publishing task. Agree how drafts and edits made during the migration will be handled so the final transfer does not replace newer work.

Check public paths.

Keep a list of important URLs and destinations. Review redirects, navigation, internal links, canonicals, files and search behavior for the changed site. A homepage check alone does not cover them.

Rehearse and accept the result.

Use a controlled copy and repeatable migration steps. Review counts, exceptions and meaningful examples, then test public and editorial tasks. Agree the release window, recovery limits and maintenance owner.