_upgrade_beforeyoubegin_upgrademethod

You can choose to upgrade using the installer, or manually using a zip or tar.gz file. In most cases the installer is the easiest way to upgrade your Confluence instance.

You will need to upgrade manually if you are:

• moving to another operating system or file location as part of this upgrade.
• upgrading from Confluence 3.5 or earlier
• upgrading from Confluence 5.6 or earlier and previously used the EAR/WAR distribution to deploy Confluence into an existing application server. 
• performing a rolling upgrade, and you need to upgrade each node individually.