Upgrade and Database Transfer
 

From the little bit I could find, on some rather old threads, it was suggested that if you want to move to a new server and institute an upgrade, it's best to transfer first, and then upgrade the software.

For reasons I won't bore you with, I don't think I will be able to do that. We've got 3.6.7 installed on a new server, and we need to move a database from 3.0.7.

Now, what kind of problems can I expect? I've got all the relevant hacks I need installed on the demo. And I don't need anything from the old forums, except threads and posts. That's all that's important for this move. We're trying to start fresh.

Yeah, I know, that must be kind of backwards. But it's kind of out of my hands at the moment. I just need to know what to expect.

You can find instructions on moving servers in the manual: Moving Servers

How do you mean you only want to move threads and posts? You can not move/restore a partial database as this will break a lot of things.

Perhaps I phrased that poorly. I didn't mean that in the sense that threads and posts were all I wanted, I simply meant that they were the only things important. I don't think I would know how to move it a partial database if I tried.

What I'm somewhat concerned about, based on what I've read here, is that we seem to be doing it backwards; moving the database to a new server that has a new version of vB already installed. What I'd like to know is what the danger is, if any, and if anything would be lost in the process.

There really is not other difference then that you would have the opportunity to test the new server during the upgrade process.

I'm in the process of doing this myself - for my trial run I did this: installed vb on the new site, played around with my new style and hacks and THEN restored my database onto it. I found that the new style on the new server was gone along with my template changes I made in it. Not in my CP anywhere.

Is there something I didn't do right? Or is that to be expected?

That would be expected, template and style data (as well as plugins) are all stored in the database, so if you did a restore you overwrote it all.

For such a move I would look at copying the old 3.0.7 database over to the new server, and then using impex to import it into your new 3.6.x forum.

Well all the hacks and template edits are stored in the database so if you restore your database then obviously any changes you made will be wiped out (to those stored on the database you've just restored.)