Please see : http://www.xwiki.org/xwiki/bin/view/AdminGuide/Installation#HInstallingtheXW... (see Install and configure a Relational Database) http://www.xwiki.org/xwiki/bin/view/AdminGuide/InstallationMySQL If you have a modified xwiki, then as the first step you have to export your xwiki (while it is using hsql). You will get a Xar file. After that you configure the xwiki to use MySql and you have to import the xar file (this will create/populate tables in mysql db). Hope this helps Regards Roopesh