Currently I am running a wordpress MU site with ~100 blogs. It's Wordpress MU version 2.8.x

Because it was so heavily used, I was asked not to update to Wordpress 3 right away. The users are worried that their plugins and themes may not work once I've upgraded. Indeed, we activated some plugins that I suspect will stop working because there have not been any updates to them in a while.

Other users are anxious to start using Wordpress 3 and the new features.

So, what I have to do now is somehow test what the update will look like, and let users log in to test how their site will look in Wordpress 3.

My question is, what is the best way for me to test the upgrade?

My the root of my Wordpress MU is at mydomain.com, and the sites are in the directory below, such as mydomain.com/henrys-blog

Thanks for your help

2 Answers 2


In this situation, I'd recommend the following:

  1. Dump your production database into your test database
  2. Install WP 3 and point it at your test DB
  3. Run the database upgrade
  4. Turn users loose on the test instance

We used a similar process on a much larger installation, and it worked fairly well. Having the second instance made it possible to use our testing resources to verify functionality without depending on the users, too.

  • That's not a bad suggestion, but how about all the plugins and themes? I suppose I could install wp3, and then move all the plugins and themes. I also wonder what to do with the mu-plugins folder.
    – jeph perro
    Feb 10, 2011 at 18:11
  • I will update my answer. Harper is totally right about the testsys which I didn't mention and I will add some more info based on your comment.
    – hakre
    Feb 10, 2011 at 21:48
  • If you need to test the various plugins, you could install WPMU 2.8.x on the system, then run the upgrades for the plugins and WPMU -> WP 3, and then test. Or, you can grab the newest versions of all plugins/themes after you install WP 3, and test them that way. The key is that your database drives all of this, so ensuring that it survives the upgrade is critical. Feb 14, 2011 at 15:18

Upgrade to latest MU version first. If you run into problems with that, report your feedback and the bugs you encounter to the MU Project.

Then Upgrade to WordPress 3.0. If you run into any problems with that step, report it to the WP Project.


As far as you're concerned for a quick test (not a mass test), you can do the test locally on a testserver (and invite some key beta-testers to test (remotely) on your machine). I would do that first anyway, because it will show if things heavily break or not.

Copy over your database and all files (that's "all blogs") to a testsystem. Re-map your domain in your hosts file to the testsystem, that will prevent you caring about domain name problems because of the migration to test. This info might be of help: Grep and Friends (collection of linux shell commands to install, backup and restore wordpress). (Feedback welcome)

So just copy over everything to the testsystem. Take something that is close to your server, e.g. probably something LAMP.

Then make a backup again (or a snapshot in case you're using a virtual system for that which is somehow recommended as those have snapshots actually build in which will make it easy to "replay" stuff and you don't need full performance).

Then do the upgrade. If you're already on the latest, you don't need to upgrade to the latest MU then, otherwise as already written I would do that. You can enable WP_DEBUG and watch warnings (I would code some logging here that will report problems with backlogs and name the plugins etc.) and all the like what's a sign of a problem here. I would fix as much that is easily fix or otherwise just kill plugins that are not expected to be updated any longer.

I have full understanding for the level of quality you want to offer to your users, just layout some key points for what you tell your users that a certain plugin or theme won't make it.

Or if you are a really nice admin, try to find out about those and perhaps you can crowd-source resources to get stuff updated. Sometimes a little higher donation (about 150+ USD or 100+ EUR) does wonders if you feel it's correct with the plugin or theme's author(s).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.