I attempted the Berkeley DB to MySQL conversion (after getting the 'disappearing comments' problem, for which a fresh install is apparently the only solution), but got:

Column 'placement_blog_id' cannot be null

And the conversion seems to have gotten so far, too! Looking at the MySQL database, it's full of juicy data. But entry categories are missing.

Any suggestions?

Well, this thread with similar errors may help - or not. Most of the folks here found that they had at least one instance of duplicate data; when that was deleted, the conversion often went smoothly. This thread (probably more germane) advocates making sure you run your upgrade scripts in the right order. I'm really hoping you'll say you're upgrading from an "older" version like 2.1 rather than 2.63 - are you?

Donna

Uh oh. I'm upgrading from 2.6 to 2.64! I suppose trying to sneak in a run of the mt-upgrade211.cgi at this point would be a bad idea?

Again, this was prompted by what appears to be a corrupted Berkeley DB relating to disappearing comments. Comments don't post (although the count is incremented correctly and the comment is e-mailed), and comments posted to older posts make all the previous comments on that post go poof as well. Reading elsewhere, it seemed I was SOL under Berkeley DB. I figured going to MySQL might allow me at least to find the glitch (probably a specific comment) and delete it.

I'm guessing it's possible the same bad Berkeley DB that's eating my comments is stopping the MySQL conversion? If so, how can I find what went bad?

FWIW, I exported the entire blog and reimported it into a new blog, and it did end up with a mis-dated older comment listed as "no author" or something... but deleting it didn't fix the problem.

Thanks for any wild guesses...

I'm really hoping I don't have to kill my setup to fix this bug. I don't suppose there's a secret cabal of Berkeley DB gurus that can fix this sort of thing for a modest fee?

So - do I understand that you were attempting to run the conversion on a corrupted Berkeley database??

Believe me, if I knew how to fix a corrupted Berkeley database, I'd definitely be a millionaire by now.