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Manually Migrate Sites to Pantheon

Learn how to manually migrate a Drupal or WordPress site to Pantheon

Manually migrate your site to Pantheon when any of the following apply:


If you are using Drupal version 9 or higher, or are moving a Drupal site and want to upgrade to the latest version of Drupal, use one of the following guides instead:

  • Large Drupal Site Archive: Site archive exceeds the import file size limit of 500MB.
  • Large WordPress Site: WordPress site exceeds 500MB.
  • Preserve Git History: You'd like to preserve your site's existing Git commit history.
  • WordPress Multisite
  • Plugin install unavailable on existing WordPress site: For example, if your existing site is hosted on, you'll be unable to install the Pantheon Migrations plugin.
  • Local WordPress Site: If your WordPress site is only on your local machine and not yet live.
  • Debug Failed Migration: It can be helpful to migrate your code, database, and files separately if the standard migration procedure failed.
Note for Composer-based Sites

The steps outlined below do not work for Composer-based sites. If you have need help migrating a Composer-based site (or any site, for that matter), site migrations are one of the services offered by our Professional Services team.

Before You Begin

To ensure a successful migration, complete the following tasks on the source site before you start:

Advanced Tips for Successful Migration


Check the contents of your current codebase for existing .gitignore files. To be compatible with the platform, using the Pantheon version is advised. Otherwise, attempts to import files to restricted paths could break the import process. See the platform-provided versions for WordPress, Drupal 7, and Drupal (Latest Version).

Local Drupal configurations

To preserve the database connection credentials for a site built on a local development environment, and to exclude them from version control, move your settings.php file to settings.local.php and add it to .gitignore so that it will be ignored by Git and included from Pantheon's settings.php when working on your site locally. Make sure that you can modify it, and restore the protections after the move:

chmod u+w sites/default/{.,settings.php}
mv sites/default/{settings.php,settings.local.php}
chmod u-w sites/default/{settings.local.php,.}

Sites running Drupal 7 must add a settings.php file that includes settings.local.php as this file is not bundled on Pantheon.

Create Pantheon Site

  1. Go to your Personal Workspace and click the Migrate Existing Site button:

  2. Enter your current website URL, choose your site type, and click Continue:

    Choose the Starting State for your Migrated Site

    Note: It is possible to upload a site running locally by putting in the local url. For example, (http://localhost).

  3. Name your site and select an Workspace (optional), then click Create Site:

    Name the Migrated Site and Optionally Choose a Workspace

  4. Click the link to manually migrate your site then select Yes to confirm:

    Choose Manual WordPress Migration

  5. Click Visit your Pantheon Site Dashboard:

    Creating Your Site on Pantheon Complete for manual migration

Now that you have a new site on Pantheon, you're ready to add the major components from your existing site: custom code, files, and the database.

Import Your Code

Your code is all custom and contributed modules or plugins, themes, and libraries. The codebase should not include the wp-content/uploads (WordPress) / sites/default/files (Drupal) directory, or any other static assets you do not want tracked by version control.

The codebase for each CMS upstream offered by Pantheon can be found on GitHub:

  • Drupal 7

  • Drupal 8

  • WordPress


    If your existing site is already version controlled and you would like to preserve the commit history, import the code from the command line with Git using the instructions below. If you prefer to avoid the command line entirely, we suggest importing the codebase using an SFTP Client such as Transmit or Cyberduck.

SFTP Client

  1. Navigate to Code in the Dev tab of your Site Dashboard. Confirm that Development Mode is set to SFTP.

  2. Click Connect with SFTP to access the credentials for connecting to your preferred SFTP client.

  3. Click Open SFTP Client to open your default local SFTP client, and enter your password when prompted.

    If you run into issues, please refer to Pantheon's SFTP documentation.

  4. Do not overwrite WordPress or Drupal core files on your Pantheon site. Upload your existing site's themes as well as plugins or modules to their locations within the root directory (code or wp-content, as shown below).

    Copy the following directories from your existing site to a matching directory in your new site's code/wp-content directory:

    • mu-plugins

    • plugins

    • themes

      As well as any other folders under wp-content that are not wp-content/uploads.

  5. Return to the Site Dashboard on Pantheon, and you should see quite a few files ready to be committed to version control. Write a commit message such as "Import existing codebase" then click Commit.


  1. Navigate to your existing site's code directory in a local terminal. If your existing code is not already version controlled with Git, create a repository and add an initial commit:

    git init
    git add .
    git commit -m "initial commit"
  2. From the Dev environment of the Site Dashboard, set the site's Development Mode to Git:

    Git connection mode

  3. Copy the SSH URL for the site repository. Do not copy git clone or the site name.

    The URL should look similar to the following:

  4. Add your new Pantheon site as a remote destination for your local code repository (replace <ssh_url> with the SSH URL copied in the previous step):

    git remote add pantheon <ssh_url>
  5. Select the appropriate version of Git running on your local machine (git --version), then merge the codebase from your new Pantheon site with your existing site's codebase:

    git pull --no-rebase --squash -Xtheirs pantheon master

    The output will resemble:

    Squash commit -- not updating HEAD
    Automatic merge went well; stopped before committing as requested

    If you haven't already configured SSH Keys, authenticate using your Pantheon Dashboard credentials when prompted for a password.

  6. Review your current index using git status, then commit all changes.

    git add .
    git commit -m "Adding Pantheon core files"
  7. Align your local branch with its remote counterpart on Pantheon:

    git pull pantheon master --no-rebase
  8. Push your newly merged codebase up to your Pantheon site repository:

    git push pantheon master
  9. Go to the Code tab of your Dev environment on the Site Dashboard. You should see your site's pre-existing commit history and the most recent commit adding Pantheon's core files.

Add Your Database

The Database import requires a single .sql dump that contains the site's content and configurations.

  1. Create a .sql dump using the mysqldump utility. For example:

    mysqldump db_name > backup-file.sql
  2. Enter your username and password when prompted to authenticate the command.

    • You might want to consider using a terminus credential fetch to avoid entering credentials for future automation steps.
  3. Run the command below to load the dump file back into the server:

    mysql db_name < backup-file.sql

You can also use the Pantheon Dashboard to add your site's database.

  1. Select the Dev environment in the Site Dashboard.

  2. Select Database / Files.

  3. Click Import and add your archive accordingly (based on file size):

    If your archive is under 100MB, upload the file directly:

    1. Navigate to the MySQL database field > click File > Choose File.

    2. Select your local archive file > click Import.

      Import MySQL database from file

      Note: If you recently imported the database and need to re-import, refresh the page and use a new filename for the database file.

Migrate Your Files

Files refer to anything within sites/default/files for Drupal or wp-content/uploads for WordPress, which typically includes:

  • Uploaded images
  • Generated stylesheets
  • Aggregated scripts

Files are not under Git version control and are stored separately from the site's code. You must create and archive of your files and export it before you can upload it.

Export Your Files

Export a tar.gz or .zip file of your files directory:

Navigate to your WordPress site's root directory to run this command, which will create an archive file in your user's home directory:

cd wp-content/uploads
tar -czf ~/files.tar.gz .

Upload Your Files

You can use the Pantheon Dashboard, SFTP, or Rsync to upload your site's files.

Pantheon Dashboard

  1. Go to the Site Dashboard, select the Dev environment, select Database / Files, and click Import to add your archive accordingly (based on file size):
  1. Select the Dev environment in the Site Dashboard.

  2. Select Database / Files.

  3. Click Import and then add your archive (based on file size) by following the steps below.

    If your archive is under 100MB, upload the file directly:

    1. Navigate to the Archive of site files field > click File > Choose File.

    2. Select your local archive file > click Import.


Follow the SFTP instructions in the Large File Transfers with rsync and SFTP documentation.


Follow the Transfer Files with rsync instructions in the Large File Transfers with rsync and SFTP documentation.

Final Migration Steps

You should now have all three of the major components of your site imported into Pantheon.

  1. Clear your caches on the Pantheon Dashboard.

  2. Confirm that everything looks and behaves as expected.

  3. Run the terminus site:import:complete <site_name> command to complete the import process.


fatal: Not possible to fast-forward, aborting.

This error may occur when trying to merge Pantheon's codebase into your existing repository as described earlier on this page in (step 5 of importing your code from the command line:

Not possible to fast-forward, aborting.

Depending on your Git version, you may see the following error instead:

fatal: refusing to merge unrelated histories

If you see this, it is possible your local Git configuration is disallowing non-fast-forward merges:

rebase = TRUE
ff = only

In this case, you will want to remove ff = only from your .gitconfig file and try the merge command again.

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