Input the all page name into [[Special:Export]], and export the all content as a XML file. Steps:
# Generate the list of all page name: #* For newer MediaWiki: Use the [https://www.mediawiki.org/wiki/Extension:OneColumnAllPages Extension:OneColumnAllPages - MediaWiki]#* For MediaWiki 1.21.2: I modified the [http://www.mediawiki.org/wiki/Extension:DynamicWikiSitemap Extension:DynamicWikiSitemap] to [http://wiki.planetoid.info/lists.phps list.php]
# Copy the list of all page name to [[Special:Export]]
# Export the ''latest'' revision of all pages (If you choose to include the all old revisions, it will takes costs time to import export the content.)
'''Other approach: Database backup'''
* [http://www.mediawiki.org/wiki/Manual:Moving_a_wiki Manual:Moving a wiki - MediaWiki] / [http://meta.wikimedia.org/wiki/Restore_Database Restore Database]
* [[MySQL_commands#Exporting_data_of_database.2Ftable_into_MySql_sql_file | Exporting data of database/table into MySql sql file]]
similar approach
* [http://www.chieftain.idv.tw/archives/2008/01/25/1337.html Reflection » Blog Archive » Export all the page names on your Mediawiki-powered Wiki]