From Joomla! Documentation
Revision as of 21:35, 10 September 2013 by Tom Hutchison
Before you begin, it is essential you know what version of Joomla! you are using. This is especially true if you are changing a major version. If you are already confused or don't know what a major version is, you should read more about the release and support cycle of Joomla! CMS Versions.
Joomla! is released with the following version designations, [major].[minor].[maintenance]. So version 3.1.5 is Joomla! major version 3, minor 1, and maintenance release 5. Since version 1.7, the updating and upgrading of Joomla! are built into the administration interface as a component. The terms updating and upgrading might be used interchangeably. In many ways, updating and upgrading are alike, but you should pay very close attention to the details of an upgrade. Upgrades would be defined as a major.minor(2.5) to a different major.minor(3.1) version or a major.minor(3.0) to a major.new minor(3.1).
Updates are an easy update to the next maintenance release, for example version 2.5.13 to version 2.5.14. This would be a maintenance release of the 2.5 version.
Upgrading from a major.minor to major.minor version can be done with the built-in core Upgrade Component. However, before upgrading you will have to do some homework. You will need to gather information which will include the following:
- Template compatibility - Will your current template work with the new version? You will have to contact the template builder to verify this information.
- Installed extensions compatibility - Make a list of installed extensions, modules and plugins. Will they work with the new version? Does the developer have a version compatibile or at the very least is there a comparable extension.
- Will the positions of modules change? Some template developers may have upgraded a template to the next version, but may have changed the module positions or added more.
- Should this be a 'live'(www viewable) upgrade? This question is a tough one and only you will know the type of upgrade you should perform. It may be better to do a 'offline'(localhost, subdomain or subfolder) upgrade, make sure your site is working fine, then move the new version to the 'live' location.
Above all, realise without the correct preparation and knowledge, you may break your 'live' site.
Upgrading to J3.1
Upgrading 1.6.5, 1.6.6, 1.7.x, 2.5.x to 3.x is covered by the following page.
Upgrading to J2.5
Upgrading 1.6.5, 1.6.6, 1.7.x, to 2.5 is covered by the following page.
Upgrading from 1.6.x(not 1.6.5 or 1.6.6 Versions)
You must upgrade to Version 1.7 first if you are on version of 1.6 below the maintenance release of 1.6.5.
Migrating (Version 1.5)
A lot of Joomla! CMS version 2.5 was based off of the 1.5 version, but at the same time there was a massive effort put into advancing Joomla CMS version 2.5 to where it is today. This effort required many core code and database changes. These changes from the Joomla! CMS version 1.5 to version 2.5 were so large and sweeping, there is no core upgrade path. If you are using a Joomla! CMS version 1.5 this will requires a migration to upgrade.