Upgrading to a new machine from an OLD machine.

[Ron]

I've got a big migration ahead of me sometime soon, from a shared reseller to a hybrid VPS.

My old machine is running MySQL 4 something and PHP 4 something.

How do ya upgrade SQL, and what happens along the way to the data that's been stored?
I'm especially concerned about special characters during the conversion. I have no idea (yet) how the data was stored under my old forum, how it was handled during conversion to the newest version.

I do know that under the old forum I could copy and paste text from external websites and the special characters looked just fine when retrieved; now special characters look like jibberish on redisplay.

Anyway, it would be a disaster for me to go through the migration and conversion and then have to roll back again as I had to last February, when that issue arose (along with the VPS' physical location problems).

So how do I figure this all out? What is involved in the MySQL migration? What do I have to watch out for with the PHP upgrade? The versions of those will be managed by JPC, as it will be a managed Hybrid VPS.

[Ron]

Thanks for all the help!

[Ron]

OK, I've got one part sorted out, I think.

The old forum expected to display charset ISO-8859-1 the new uses utf-8. I don't know what conversions the old forum did (or didn't do) before data was stored in the database or if anything was converted on display of the stored data, but I just MUST assume that if there was any character conversion during the conversion to the new forum it will all work with utf-8.

I found in my template I was setting charset=ISO-8859-1 for my webpages. I tested one corrupted page with a charset=utf-8 header and the page looked perfect. This was driving me crazy because not only did pages look different between my subsystems, but also they looked different from before on both platforms. On top of which, the forum now does not allow for user-entered html at all, and it displays old html as text kinda sorta. I didn't realize I was dealing with multiple fundamental structural changes. I assumed there were data changes, not just display changes. Go figure. I should have known better with phpBB.

So now here comes the old question that I asked almost a year ago -- how to implement this changeover to utf-8 from ISO-8859-1 while mitigating risk? I know that some don't seem to grasp the issue, but this change could effect 75% of my business.

(A similar change (actually a much more minute change in that it did not affect rendering at all) with a minor typo once caused me to lose 80% of my traffic from Google for 6 months.)

Ahh well. I guess I'll just go off and figure it all out on my own. If anyone else has phpBB 2 to phpBB 3, mysql 4 to mysql 5 and php 4 to php 5 migration issues or advice, lemme know. Maybe we can commiserate.

[Gwaihir]

I found in my template I was setting charset=ISO-8859-1 for my webpages. I tested one corrupted page with a charset=utf-8 header and the page looked perfect.

Note that you can't just set a charset header in the html headers, but you can set one in the http headers as well (via an apache setting). Do check if it isn't there already without you being aware of it. It's best to set both and make sure they match. If you do set both and they don't match, do expect issues. According to specs the http header should be followed, but not all browsers do this.

[JPC-NickO]

Hi Ron,

Do you have multiple sites using databases or just one? Are they all MySQL4/PHPbb?

If I were you I'd have support setup the Hybrid with our standard configuration including PHP5 and MySQL5. (I now recommend to use MySQL5 exclusively if possible. PHP4 is really old.)

After you've got that all setup the way you like it try to move the site into a test account.

Take detailed notes

1. The first setup is to modify the configuration so that will will work on a test url: e.g. http://vpsip/~user/ which can involve hacking at the configuration, modifying the app configuration settings in the database (wordpress requires this), or just changing the .htaccess.
2. Now get the forum to work. Doesn't matter if it's displaying funny characters. You can mess with that after you know the forum is working. (99% of the time it should just work. If your using really old stuff you may have to upgrade to the latest version)
3. Fix the character set issues. Most of the time this just involves dumping the database, using iconv to convert the text to the right format, and maybe modifying a few settings in the application. Google "App UTF8".
4. Verify everything displays properly.

Now that you've got it working it's time to delete it and try it again from your notes verbatim. This ensures that you can do it again quickly and effectively when your really transferring the site.

If that works good move on the next major site you need to move and do the same thing. Notes and all.

Actual migration:
Setup some new custom name-servers for the hybrid (these should be different form the ones you use on shared/reseller). Wait for these to propagate and make SURE they are setup correctly. Broken name-servers are a very common issue on VPS/Hybrid/Dedicated. Just because it works doesn't mean it's right.
Make sure you've removed any bit of your testing from the hybrid.
Make a page on the old server that says something like "We are currently migrating this site." etc. I like to do this with a .htaccess redirect. Makes it easy to take a site offline and online quickly.
When your ready to start turn on the offline page.
Transfer the site.
Make the changes according to your notes.
Update the name-servers at your registrar for the domain.
Remove the offline page from the destination server only. We don't want people posting on the forum on the old server. If done right only the people resolving to the old server will hit the offline page.
Advanced/Optional: Edit the DNS zone on the old server to point to the new server. This may speed up the transition slightly. If you intend to do this reduce the TTL values for the zone the day before.
Your pretty much done. In a day or two remove the account from the old-server.

It's very important that you verify your DNS configurations during and after the move.

[Gwaihir]

Edit the DNS zone on the old server to point to the new server. This may speed up the transition slightly. If you intend to do this reduce the TTL values for the zone the day before.

Isn't it a good idea regardless, to reduce the TTL for the DNS a day or two before you change nameservers and IPs?

[JPC-NickO]

Yes, it always a good idea to reduce the TTL values enough before the migration that you can be sure the original cached records have expired. I generally say a day because it's cPanel's default value for the SOA expiry.