Updating Mediawiki

I have been updating from MW 1.19.4 to 1.33.1. This is in consequence of a rather belated upgrade from Ubuntu 14 to 16.

Updatng to a new version of Mediawiki is not all that obvious, especially if you have several wikis. It is generally safer to make a complete copy of all the files and DB tables than to update in place. The sequence below ensures that you do not alter any currently working files.

• Use mysqldump to back up each DB into a separate dump file. If all your wikis share the same DB then there will be just one file.
• Create the new DB(s).
• Restore each dump file to the appropriate place.
• For each wiki make a complete copy of the Mediawiki master files, usually found in /usr/share. or /var/lib If you symlink them you will have problems later.
• Create a new LocalSettings.php for each wiki.
• Copy each old wiki's images/ directory to its new location.
• Change the ownership and permissions on the trees you have created so that your web server, and only your web server, can access them (Mode 750).
• Change into each wiki's root directory and run php maintenace/update.php. This is the step that will go wrong if you used symlinks, above: it will read the wrong LocalSettings.php.
• For any skin in your /skins directory that you wish to use, you must enable it in your LocalSettings.php file. For example, to enable Vector, add the following. If you have multiple skins, each must be enabled with a separate statement:

      // mw.v 1.24.x or less
      require_once "$IP/skins/Vector/Vector.php";
      // mw.v 1.25.x or above
      wfLoadSkin( 'Vector' );
  

• In order to load a file with any suffix, e.g. .wpd, you willneeed toset $wgVerifyMimeType=false in LocalSettings.php, apart from adding the file type to the permitted list.
• You will probably have to update maxFileUpload and maxPostSize (or post_max_size and upload_max_filesize) in /etc/php/$version/apache2/php.ini.
• Update the web server's configuration to point to the new wikis.
• Check that MySql's socket directory, usually /var/run/mysqld, has mode 755, or Apache will not be able to connect to your DB.
• Restart the web server

You now have two complete copies of your wikis. When you are confident that the new versions are correct you can drop the old DB(s) and delete the old file trees.