This chapter explains how to upgrade an existing MantisBT installation.
Start by Performing the steps described in Section 2.3, “Pre-installation / upgrade tasks” above.

1. Put the site down for maintenance

   cp mantis_offline.php.sample mantis_offline.php

• This will prevent users from using the system while the upgrade is in progress.

  1. Always Backup your code, data and config files before upgrading !

• This includes your Mantis directory, your attachments, and your database. Refer to Section 2.10, “Backups” for details.

  1. Copy the configuration files

• To preserve your system settings, you should copy the files listed below to subdirectory config of the new installation.
  config_inc.php,
  custom_strings_inc.php,
  custom_constants_inc.php and
  custom_functions_inc.php.

• Note
  The above list is not exhaustive. You might also have to copy other custom files specific to your installation such as logo, favicon, css, etc.