UPDATE: I'm changing this first post to clarify where this journey went.
There is now a backup server for http://wiki.alioth.net
. It is located at http://wiki.maikschulz.de
. This is an "official" backup with support from Winston, who also gave me the keys to his wiki installation to take care of it. This includes upgrading the MediaWiki software and installing extensions.
The backup is performed automatically every day at 5am CET. It takes around 10 minutes and performs an rsync of the MediaWiki installation, a full dump of the MySQL DB except the "text" and "object cache" tables, and an incremental dump of the "text" table. The only difference between the main server and my backup is that I set my backup to read-only mode. When you want to edit a page on the backup server you will see a message that informs you accordingly and your changes cannot be saved. This is to make sure that no one accidentally changes wiki pages there.
Winston also made Ahruman and myself Bureaucrats on the wiki. This means we can change privileges of other wiki users, e.g. to make new Administrators.
Last not least I changed the [wiki]Main Page[/wiki] of the wiki to tell new users to contact me here via PM for an account. In fact, any administrator can create user accounts. It would be good if the other admins would add themselves on the main page while they are frequenting the BB and remove themselves e.g. when they go on vacation and won't have connectivity.
cim continues to have shell access to my server.
In order to test e.g. the MediaWiki version upgrade or extensions, I also setup a separate copy of the wiki at http://sandbox.maikschulz.de
. It is not regularly updated from the main server but has a snapshot of the wiki from a few weeks ago. Still, enough to function as a testbed.