You should read through the comprehensive Upgrading_WordPress WP upgrade documentation site before attempting to upgrade WPMU. However, be sure you download the MU version of the software found at http://trac.mu.wordpress.org/browser/tags, not the software found linked on the "Download" tab above. In summary, we recommend you:
Remember to backup your database and files. The link above has instructions to help you do this.
If these instructions are out of date please update them. That's much better than just complaining on the forums.
Check your Version. You can find the version of WPMU by looking at the page source of any page. If you are viewing the site you should see <meta name="generator" content="WordPress 2.5.1" />, keep in mind the WPMU version was deprecated by 1 (prior to WordPress MU 2.6--see below), so 2.5.1 was really 1.5.1.
After 1.5.1, the version number jumped to 2.6 to sync with regular WordPress and avoid confusion. It will use letters to represent minor versions.
The last version of WPMU was 2.9.2, and after that, all install could upgrade to WordPress with the network enabled (multisite).
Under the Site Admin menu, there is a tab or sub-menu item called Upgrade. This does not change any files. If you have not upgraded any files, clicking this will do nothing.
This is the last step in the upgrade process. When you click it, it compares the version stored in the database with the version number in the files. If they are different, it runs any needed checks against the database and makes adjustments accordingly. It will step through every blog on your system in batches of ten and display a list as it does so.
If for some reason you can't make it all the way through, the same upgrade process will run in the background automatically as soon as someone signs in to the admin area of their blog.
With this version, WPMU is merged with WordPress core. Upgrades after this point will be the same. to move from WPMU to 3.0, you may use the internal auto-upgrade or manually overwrite files.
There are two extra changes.
RewriteRule ^(.*/)?files/(.*) wp-content/blogs.php?file=$2 [L] and change it to this: RewriteRule ^(.*/)?files/(.*) wp-includes/ms-files.php?file=$2 [L]
define( 'NONCE_SALT', '6xF{&bvT_PAsmbnG<72.dJH>D8R8M!M{~r.U]-~j:rG!g!0(g7hvz)+/h9 IY7Ge' ); It will give you your own salt, this is an example.
Same procedure as below.
This is the same procedure as many of the other version upgrades below.
Copied from the instructions for 1.5 to 2.6, cleaned up a bit, and adjusted for the changes in 2.7.
define('DOMAIN_CURRENT_SITE', 'yourdomain.tld'); // don't include "http://www." at the beginningdefine('PATH_CURRENT_SITE', '/'); // this should be the path relative to your domain. For instance, if your WPMU installation is located at 'http://www.example.com/blogs/', then the value of this constant should be set to '/blogs/' instead of just '/'define('BLOGID_CURRENT_SITE', '1');define('ADMIN_COOKIE_PATH', '/');define('COOKIE_DOMAIN', '');define('COOKIEPATH', '');define('SITECOOKIEPATH', '');define('NONCE_KEY', ''); // replace '' with value from http://api.wordpress.org/secret-key/1.1/define('AUTH_SALT', ''); // replace '' with value from http://api.wordpress.org/secret-key/1.1/The version number is being bumped to 2.6 rather than 1.6 because of version confusion. Minor MU versions will probably append a letter to the version.
Notes: In this version, the signup page uses "blogname" instead of "blog_id" to avoid confusion with the global variable of the same name. Signup plugins will break if not updated!
References
Tip: if you keep getting a redirect on login error, try calling the upgrade page directly (yourdomain.com/wp-admin/upgrade.php). If that works, click the link, then try logging in again.
First approach (tested on WPMU 1.2.2 without subdomains):
This upgrade introduces tagging of posts. New tables, including 3 per blog, are created for this purpose, and are synchronised, during the upgrade process. Reference 1 provides more details. In some cases, such as where the server is heavily loaded or the number of blogs is large, this process has not completed successfully. A beta taxonomy synch script may help in this situation.
References
WPMU 1.3 assumes your database tables use the utf8 default character set. If you started with an early version (e.g. 1.0 RC4) you may find your tables are defined to use the latin1 default character set. If so, they must be changed to use utf8 prior to the upgrade. Unless this is done, strange symbols (e.g. Â, i.e. A with circumflex) may appear in amongst blog content following the upgrade2 3. The process is described in Reference 1.
References
An attempt to use code from WPMU 1.3/WP 2.3 generated an error that 'register_sidebar_widget' was not a correct function. A quick search of the WPMU code seems to show a 'wp_register_sidebar_widget' but it appears to have different parameters. Can anyone help?
(Question asked at [[1]]
Instructions needed
Instructions needed
Upgrading a recent version of WPMU from after June 22, 2006 or when Release Candidate 1 was published should be simple enough.
* Download the newest version and unzip it somewhere. * Shut down the site by stopping Apache. It's easier this way. When you're comfortable with upgrading this step may be skipped. * If you haven't modified any files then overwrite your current install with the files from the newer version. * If you have modified files you'll have to be careful to not overwrite those files. * Examine the new htaccess.dist and compare it to the old ".htaccess" file. Add any new lines and remember that "BASE/" should be replaced with the path to your web site. * Restart Apache. * You may need to upgrade the databases tables of each blog. This can be done by visiting "Site Admin"->Upgrade while logged in as the site admin. This may take a long time.
Before Version 1, RC1 was released we used a wp-inst directory to hold the core wordpress files so there is more work to do upgrading.
* Download the newest version and unzip it somewhere.
* Shut down your site by stopping Apache. You really should do this as there are so many files moving about.
* Presuming your site is installed in /home/www/htdocs/:
o Delete /home/www/htdocs/index.php and /home/www/htdocs/.htaccess
o Move /home/www/htdocs/wp-inst/* to /home/www/htdocs/
o If you haven't modified any files then overwrite your current install with the files from the newer version.
o If you have modified files you'll have to be careful to not overwrite those files.
o Copy the new /home/www/htdocs/htaccess.dist to /home/www/htdocs/.htaccess and edit .htacces, replacing "BASE/" with the path to your web site. In this case it would probably be "/".
* Restart Apache and test, test and test things.
* You may need to upgrade the databases tables of each blog. This can be done by visiting "Site Admin"->Upgrade while logged in as the site admin. This may take a long time.
* If you used WPMU with sub-directories prior to June 2006 you will come across a particular problem when upgrading. Read [[2][bug #85]] for more.
If things go wrong you can always restore things from the backup. You did backup all your files and database first? Hang your head in shame if you didn't!