Migration and upgrade
So you have the raw wikitext? Let's hold off a little longer - if we get the original that would be ideal of course, but this is good to have as an alternative. Maybe a few key pages should be updated ASAP - rumbles for example. And if we don't get the originals back, then I'm not too concerned about authorship - the wiki already went through a migration once.
Daily backups are ~250MB. I have daily for a week, then weekly for a month, then monthly. So total will be under 10GB for a long time. Extra backups can't hurt :-)
Yes. I have raw wikitexts. They also come with authorship, but I guess there is no way to stick it back.
Ok. I can manage 10GB. No problem. Though, it is sounds very wasteful for a few kB of text files changed weekly.
I don't know if there is an easy way to get diffs - it must be possible for mysql slave mirrors, but the wiki is small so we can be lazy with our backup mechanisms ;-)
I've been using mysql slaves for years, and it is not only easy to set up, but also a perfect candidate as a readonly mirror of the wiki.
And the slave can be set as master anytime, making the mirror the main wiki when the original one goes down. This ensures zero downtime if set up automatically.
Anyway, this is not a replacement of monthly backup. If a hacker managed to run drop db, the slave will also be destroyed.
Could you elaborate on mysql slave? I would like to try it, and maybe even host readonly replica.