Transfer GitLab Pages storage location w/o downtime

doc/administration/pages/index.md

@@ -462,6 +462,34 @@ are stored.
 
 1. [Reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure).
 
+Alternatively, if you have existing Pages deployed you can follow
+the below steps to do a no downtime transfer to a new storage location.
+
+1. Pause Pages deployments by setting the following in `/etc/gitlab/gitlab.rb`:
+
+   ```ruby
+   sidekiq['experimental_queue_selector'] = true
+   sidekiq['queue_groups'] = [
+     "feature_category!=pages"
+   ]
+   ```
+
+1. [Reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure).
+1. `rsync` contents from the current storage location to the new storage location: `sudo rsync -avzh --progress /var/opt/gitlab/gitlab-rails/shared/pages/ /mnt/storage/pages`
+1. Set the new storage location in `/etc/gitlab/gitlab.rb`:
+
+   ```ruby
+   gitlab_rails['pages_path'] = "/mnt/storage/pages"
+   ```
+
+1. [Reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure).
+1. Verify Pages are still being served up as expected.
+1. Unpause Pages deployments by removing from `/etc/gitlab/gitlab.rb` the `sidekiq` setting set above.
+1. [Reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure).
+1. Trigger a new Pages deployment and verify it's working as expected.
+1. Remove the old Pages storage location: `sudo rm -rf /var/opt/gitlab/gitlab-rails/shared/pages`
+1. Verify Pages are still being served up as expected.
+
 ## Configure listener for reverse proxy requests
 
 Follow the steps below to configure the proxy listener of GitLab Pages. [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/2533) in