Confluence server migration vs restore

[Brad Solomon]

The page Migrating Confluence between servers recommends copying over the entire contents of CONFLUENCE_HOME directory to the new server.

And yet, Confluence also has a seemingly more lightweight process to Restore a Site that consists of restoring from a plain XML backup.

Why is it preferable to use the full CONFLUENCE_HOME for migrating Confluence Server to a new server, versus restoring Confluence using the XML backup on the new server? What are the functional differences between these two approaches? What is the downside of migrating Confluence to a new server using the Restore a Site/XML backup procedure?

[Brad Solomon]

@Mirek we are doing the following:

- Migrating from one Amazon ECS cluster to another, using exact same Confluence Docker image

- Migrating from one database endpoint to another, both RDS using Microsoft SQL Server

Which of the two approaches (XML backup or full migration of CONFLUENCE_HOME) would be the best fit for this?

[Mirek]

Hi @Brad Solomon 

Using XML backup is loading whole configuration and data into existing database on running Confluence instance that was already installed (if there is some data it would be overwritten). It is primary used to restore instances than move between server but it is good to try it when you want to change databases (e.g from MySQL to PostgreSQL) or migrate from/to Cloud.

When you physically migrate between servers (e.g want to change infrastructure / OS) you migrate first application just by copying files, than database (you need a database backup) since db data is not stored in CONFLUENCE_HOME and other files (e.g attachments if not in HOME). You need to make sure that configuration of the server is identical. If something would be different and you would not change configuration files application might not start or work properly.