Upgrading from WPMU to WP 3.0
Posted by andrea in Now that 3.0 is officially released, you may have seen an upgrade notice in the backend of your WPMU install. While the process is generally just clicking the upgrade button, there are a couple of additional steps to fully smooth out any merged changes that occurred.
First, backup your database(s) and the entire wp-content folder. Then hit the Upgrade button.
You’ll notice immediately after doing the auto-upgrade that there’s a yellow message in the admin area that states the following:
The wp-content/blogs.php file is deprecated. Please remove it and update your server rewrite rules to use wp-includes/ms-files.php instead.
So, go ahead via ftp or through your web hosts control panel and delete the blogs.php file from the /wp-content/ folder. It’s been moved and renamed to /wp-includes/ms-files.php for you already.
You’ll now need to update your .htaccess file so your uploaded images will continue to display properly for your users. Find the line that says:
RewriteRule ^(.*/)?files/(.*) wp-content/blogs.php?file=$2 [L]
and change it to this:
RewriteRule ^(.*/)?files/(.*) wp-includes/ms-files.php?file=$2 [L]
You will also need to add a nonce salt to wp-config.php. You’ll get a warning about it and it will look similar to this:
define( 'NONCE_SALT', '6xF{&bvT_PAsmbnG<72.dJH>D8R8M!M{~r.U]-~j:rG!g!0(g7hvz)+/h9 IY7Ge' );
Stuff it in there with your other salts.
If you decide to upgrade manually, replacing the new files, make sure you snag the new TwentyTen default theme, as well as make the above changes. Feel free to finally dump Kubrick & Classic. 
One of the things you will instantly notice is the renaming of the menus. Now that you’ve completed the basic upgrade, make sure your entire network gets updated by visiting the Super Admin -> Update page. As before, this will step through the blogs (now sites) a chunk at a time, applying any needed database changes.
Additional notes:
Since you are upgrading from WPMU, you are already running a network of sites. Please DO NOT follow the Create a Network instructions, as you will not need them.
If you’re running our multi-site plugin, no worries! It has worked smoothly for us and reportedly others who have upgraded MU.
In case you are running a version of WPMU earlier than the 2.9 branch, please step through upgrades manually to 2.9.x as outlined in the codex. Then you can continue as above.
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46 Responses to “Upgrading from WPMU to WP 3.0”
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Thanks for this. If upgrading manually, from WPMU 2.9.2 to WP3, do you need to edit wp-config.php to enable network?
Twitter: andrea_r
says:
Like I said near the end, if you’re on MU, you’re alreayd running a network. So no, you don’t need to enable it.
thanks. I read that but I wasn’t sure if the auto-upgrade did that for you. Thanks again.
Is there anything special we’ll need to do, or do we even still need to use Donncha’s Sitewide Tags plugin?
Twitter: andrea_r
says:
Just the steps above. Donncha’s SWT plugin is still needed. The devs didn’t roll anything like that in.
Twitter: robertgrinde
says:
Which multi-site plugin are you talking about? This one: http://wpmudev.org/project/Multi-Site-Manager ?
Twitter: andrea_r
says:
The one we sell here on the site. It’s for running multiple networks.
Look in the top menu bar.
Twitter: robertgrinde
says:
I see, I am running this one now serving about 1000 blogs on two domains. Do you know if it is possible to switch to yours instead without much hassle?
Twitter: andrea_r
says:
Honestly, it’s been a while since I even looked at the older plugin (it hasn’t been updated in a very long time) so I really don’t know. Ours provides the interface to make more networks (sites in mu). when you remove it, those still exist and function because it’s all saved in the database.
we’ll be coming out with an update soon, probably next week.
Twitter: robertgrinde
says:
I see, would you be able to email me a sample database structure so I can check for myself if it is much different?
@Robert – the MU multi-site/WP network use the existing MU/WP tables. As far as we know, none of the multi-site plugins created tables.
Twitter: JellyBeen
says:
The process for upgrading from WordPress MU 2.8 follows these exact same steps, too.
Twitter: andrea_r
says:
good to know!
Does this comment mean you can directly upgrade from 2.8.x to 3 without first going to 2.9.x?
Thanks in advance for clarifying.
Is the mu-plugins directory still in use???
Twitter: andrea_r
says:
It sure is. Single WP has supported the mu-plugins folder since 2.7.
If, after upgrading, you find you no longer have Super Admin access, check to make sure your account is still listed as a Super Admin. You may need to use a database tool to do this.
This is what happened to me…
On my original install of WPMU 2.x I used phpMyAdmin to manually change the name of the super admin account. The name I use has an uppercase letter in it. For this example, I’ll use “Frank” (not the real name).
Example: admin was changed to Frank
After the upgrade, Frank (admin) no loner has Super Admin privileges.
Super Admin was listed as “frank” before 3.x and had to be changed to “Frank” for 3.x to work.
Twitter: andrea_r
says:
Nice catch.
I’ve seen one person with the same issue, but has no clues.
Twitter: leisegang
says:
When i run the upgrade blogs script it stops at the same blog every time. around 50 blogs out in the upgrade.
is there any way of finding out what causes this or read any log?
Twitter: andrea_r
says:
MU doesn’t generate any logs for this. If it is the same blog, you could try logging in to the backend of that blog, which will force the same upgrade.
It’s hanging becasue there’s something wrong with that blog in particular. So sort out any issues there.
Happy Father’s Day RON!!!!
Long time no talk to you!
I would like to upgrade from wpmu 2.7.1
to wordpress 3.0.
You helped me with my website before. And I couldn’t tell you what was done (I’m still ignorant to a lot of the wpmu stuff. What do you recommend?
I’d recommend upgrading to
MU 2.8.6 and then 2.9.2. Once you are at 2.9.2, you can upgrade to 3.0 via the automatic upgrade.
Twitter: leisegang
says:
I was just wondering what $wpmuBaseTablePrefix is replaced with.
This is used in a lot of plugins i use on my site.
Twitter: andrea_r
says:
Please read this thread:
http://mu.wordpress.org/forums/topic/18436
that function was deprecated 3 years ago.
I’m pretty new to this. I’ve made updated to 3.0 and made the changes in the initial post except for the .htaccess change. I’m assuming that file already exists but I’m not sure where it is located. I’ve done a FIND use File Manager in each of the directories but cannot find. Any guidance would be helpful. Thanks!
Twitter: andrea_r
says:
Just make the htaccess change and don’t worry about the file. If it hasn’t been removed already, changing the rewrite rule will effectively ignore it.
I found it using the Legacy File Manager and made the change to the .htaccess file. Does the .htaccess_MU need to be changed at all?
Twitter: andrea_r
says:
There is no .htaccess_MU file. You or someone working on your site must’ve renamed a file to keep a copy.
Okay. When I first did the upgrade to 3.0, there was text at the top of my dashboard stating to change my wp-config.php file by adding this statement…
define( ‘NONCE_SALT’, ’8f]uMwtil+0Zk~/ESoSyW5wl$z,:hZmbYky=MzWsW4K)JZSM&9jh0#;#5}+>TR=1′ );
however the 1st post here says to add this…
define( ‘NONCE_SALT’, ’6xF{&bvT_PAsmbnGD8R8M!M{~r.U]-~j:rG!g!0(g7hvz)+/h9 IY7Ge’ );
Do I need both statements or only one of them?
Which one?
What do these statement do?
Twitter: andrea_r
says:
Mine is an example. Use the one you were given in the backend.
Thanks!
[...] has written a great guide about domain mapping in Multisite mode in WordPress 3.0.The excellent WPMU Tutorials has a fantastic guide on how to upgrade from WordPress MU to WordPress 3.0 Multisite.Custom Post [...]
Thanks, this helped give me confidence to make the jump from WPMU 2.9.2 to 3.0.
Only 1 hitch so far… my images have dropped off from my sites on images using the WP upload feature.
Here’s an example for one of the sites settings:
upload path: wp-content/blogs.dir/3/files
fileupload URL: http://sitesubscribe.com/4everyoungmbs/files
Here’s a URL on the actual page where the image doesn’t show:
http://sitesubscribe.com/4everyoungmbs/files/2010/03/testimonials.jpg
When I upload new images they still don’t show up.
I checked permissions on ‘wp-content/blogs.dir’, it is 777.
In this instance I’m using the ‘sub-folder’ config.
Do I need another htaccess edit beyond the one you already mentioned? (changing blogs.php to ms-files.php)
Any ideas?
Thanks.
Forget it… just 5 minutes after posting this I found I had not changed the htaccess part correctly… I need to change not only the blogs.php file, but the directory to ‘wp-includes’ as well.
That fixed it.
So virtually a seamless migration except for my own typo. And had to delete a couple of malfunctioning plugins.
Hey Andrea,
Used your post doing the upgrade from WPMU to 3.0 last night. Worked a treat, thanks
Fiona
Thanks for the tutorial! When I upgrade from WPMU 2.9.2 to WP 3.0, the site admin pages take 2+ minutes to load. I have gone through all steps mentioned on this and other tutorials, but every time seem to have the slow admin page load. Do you have any recommendations or troubleshooting tips that you would recommend?
Thanks!
Try clearing your browser cache. Also, did you upgrade the network to 3.0 through the upgrade network page?
I have been testing WordPress 3.0 on a development server for a while before I am about to upgrade my 2.8.6 main site. One question I have, is it possible to make all my sites use the new Twenty Ten theme? Most, if not all, of my sites are using the K2 theme currently and I was wondering if there was a way to this. Thanks.
Twitter: andrea_r
says:
All newly created sites will use twentyten.
to get the Kubirck ones using the /default/ theme to now use 2010, the quick & dirty way is to rename or remove Kubrick. That’ll trip each blog into using the new default.
Hey Ron & Andrea,
Thanks for your guidance today on Twitter @andrea_r. I was able to get my WPMU 2.9.2 installed from the Automattic svn repository finished correctly by doing what you suggested: I simply had to install via the WP.org core svn repository. When I tweeted there were errors I found out those were being caused due to my failure to copy over the wp-content directory with all my installed plugins.
So, all is groovy except I’m also not getting uploaded images to show (as was stated earlier by @SiteSubscribe)
I’m wondering, Ron, if this is due to the rewrite line not being translated and inserted in the proper place in the Nginx conf files.
rewrite ^.*/files/(.*) /wp-includes/ms-files.php?file=$1;Any thoughts? I’m messing around trying to figure it out, but thus far am striking out. Boo!
Thanks in advance.
Hello Andrea,
If you remember last time I had discussed about installing WP 3 multi site in a sub-domain and then point the wild card entry to that sub-domain folder so that I can use the domain root for other script and at the same time be able to create different sites with sub-domains enabled.
Well, I confirmed this from my host and they said that its very much possible.
Currently, WP 3 multi site is installed in the domain root. I wanted to know that how do I can move this installation to a folder of some sub-domain. Moving means, making changes to the necessary configurations where ever applicable.
Any help will be highly appreciated.
Regards,
Alok
Twitter: andrea_r
says:
It really depends on the host. Yours will do it (point the wildcard to another folder), many shared hosts won’t.
For moving the install.. just move the files. Go through the database with a search & replace on the domain name.
I moved all the files, searched the DB for the primary domain and replaced it with the sub-domain. Also edited the wp-config file and changed the domain there also.
Everything worked but I am not able to login to other sites. Earlier when I used to click on My Sites > Dashboard link, it used to login to that site directly. But now I get the login page. Even though I enter the correct login details, it still shows the login page again.
Just won’t understand what to do.
Twitter: http://garfo.ru
says:
It seems that if this update from WPMU to WP 3.0, but not a clean install and the base network already includes the line:
define (‘MULTISITE’, true);
not necessary and even prevented, with it I get an error:
Error establishing a database connection
Hi Andrea,
I wanted to know that is it possible to create sub-sites in sub-domains.
For e.g. the main site is example.com and it has site1.example.com.
Now I want to create site1.example.com/sub-site1.
I desperately need such feature to implement it for one of the projects.
Regards,
Alok
Thanks, worked like a charm. ^_^