If you plan to upgrade your confluence installation from a very old release (e.g. version 2.5.6) to the newest version 3.0.0_01 you can make your life easier if you take the chance to export and import your whole content items with the administration interface. Just login into your old confluence instance, make a content export including all attachments. After that you can simply import the generated export ZIP-File from your file system to the new confluence instance 3.0.0_01. During the import of the content confluences also manages the update of the whole search index. Also all users, user groups, page and space permissions are available after the import

I was really suprised how easy an update of confluence is. Just export and import. And you could make it – it depends on the amount of your content items and attachments – in just few mintues.

Das Upgrade war sehr einfach und hat ungefähr 5 Minuten gedauert