Backing up the wiki

Backing up the wiki without server shell access, requires Python v2 (v3 doesn't yet work).

Run the the WikiTeam Python script dumpgenerator.py from the command-line to get an XML, with edit histories, dump and a dump of all images plus their descriptions.

A XML dump does not create a full backup of the wiki database, the dump does not contain user accounts, etc. Extensions and their configuration are also not backed up, also file types other than images don't get saved.

Full instructions are at the WikiTeam tutorial.

Restoring from backup με λίγα λόγια
Assumes economical shared Linux hosting, with jailed shell access. Maybe out of date by now.

See MediaWiki.org for more detailed instructions, (specifically Manual:Importing XML dumps.

Delete the setup files now no longer required: mediawiki....tar.gz, sdiyinfo....xml, Scribunto....tar.gz and the public_html/images/ folder.
 * Use cPanel &gt; MySQL to create db e.g. wiki, user e.g. root, grant all privileges to the user and set a password e.g. Whatever123
 * SSH into your server
 * or whatever.
 * (replacing x.xx as apropriate for current version).
 * (don't put wiki pages in the root directory of the site)
 * Upload the XML dump and images folder to the server, to e.g. public_html/
 * Wget and extract Scribunto extension into the extensions folder, e.g. e.g. public_html/w/extensions.
 * Open your wiki with a web browser e.g.
 * Follow the link. Complete the steps that follow. Leave most options at defaults. Except for:
 * Database character set select UTF-8.
 * Copyright and license to Creative Commons Attribution-ShareAlike
 * Extensions select at least Scribunto
 * Tick Enable file uploads
 * Tick Enable Instant Commons
 * Copy LocalSettings.php onto the server wiki folder, e.g. w/.
 * In the shell do
 * If that works repeat without
 * If that works repeat without

LocalSettings.php

 * Add filetypes to the default array:

Tweaks

 * robots.txt and short URLs
 * add to .htaccess  and   for all toxic IPs availble from Stop Forum Spam
 * Rename folder w/mw-config

Useful extensions
Follow links for downloads and instructions.

Already installed above: Installed with MediaWiki: Download and install Semantic Bundle. Installed with Semantic Bundle: Also install separately:
 * Scribunto
 * Cite
 * Gadgets
 * ParserFunctions
 * PdfHandler
 * Renameuser
 * SyntaxHighlight GeSHi
 * WikiEditor
 * External Data
 * ReplaceText
 * Widgets
 * BreadCrumbs
 * CategoryTree
 * CharInsert
 * CollapsibleVector
 * ConfirmAccount
 * ContributionScores
 * ExternalLinks
 * MP3MediaHandler
 * MultiBoilerplate
 * ReassignEdits
 * SandboxLink
 * SidebarDonateBox
 * SimpleMathJax
 * TemplateSandbox
 * UserMerge

Templates
Most templates should have been restored. Where they haven't it's simpler to use Wikia templates than those from Wikipedia. Obtain the required XML data via Special:Export. Do not include the full history or the file will become too large. Tick Include templates so that any dependencies are included. Then on the SDIY wiki use Special:Import. Also copy any relevant styling.

Because of CC-BY-SA licensing considerations try to acknowledge the source of imported templates.

Restoring from backup - Miraheze
For free of charge MediaWiki hosting, without advertising and with the server installation maintained by expert volunteers, use miraheze.org.