WordPress Multisite

Formerly known as WordPress MU, WordPress Multisite is a feature of the famous WordPress blogging/CMS application that allows you to create a network of sites, similar to how WordPress.com works.

NOTICE: While Multisite can be run on shared hosting, we do not provide wildcard DNS for subdomains. If you wish to use Multisite with subdomains, you will need to use a VPS, or manually map subdomains.

Remember, you must remain within resource usage limits if you run Multisite on shared hosting.

Warning/Important Notes
WordPress Multisite is not for everybody. Some things you must know:


 * WordPress Multisite support is NOT PROVIDED BY DREAMHOST.
 * Multisite is not for WordPress beginners. You should already know how to use WordPress before considering Multisite.
 * Users should have basic knowledge of PHP, MySQL, how to edit files on the server, and how to review error logs in case of trouble.

Again: It is not for beginners.

Before you install
In some cases, you may not need to install Multisite. You may be fine with a single-user install. Some questions you want to ask before you begin:


 * Are you creating multiple blogs with different admins?
 * Are you proficient in PHP, MySQL, and reviewing logs for errors?
 * Are you confident in providing support for (potentially) many users?
 * Do you want to give each blog a subdomain or a subdirectory? Subdomains require wildcard DNS. In some cases, it may be more trouble.

If you're confident, get ready to install!

Installing
Below are some tips and steps that should help you get Multisite installed and running on your domain.

Requirements
Things needed for this process:
 * 1) A domain or subdomain. (e.g. domain.com)
 * 2) A domain using DreamHost's PHP5 cgi (this is 'very' important)
 * 3) Patience

Wildcard Subdomins
If you're on a VPS or Dedicated server, you can use a wildcard DNS entry. To do this, you will need to contact the support team and request that this be set up for you. Your request will not be processed unless you are on a PS server. Just let them know that you are installing WordPress Multisite and that you need a wildcard DNS entry, and a wildcard ServerAlias entry set up for the domain you're installing it on.

DO NOT, DO NOT, do not skip this step, or use the panel or simply enter an asterisk"*" as a CNAME record on the panel. This is ineffective and will cause tremendous problems down the line.

Manual Subdomains
If you're on shared hosting, you can't have wildcard DNS, but you can manually create them. The easiest way to do this is to go to your domain manager in Panel and create a new subdomain (foo.example.com) that mirrors your main domain (example.com).

Installing

 * 1) Install WordPress (You can use the one-click installer for this if you wish)
 * 2) Activate Multisite

Make sure you read through all the steps.

Mapping Domains
It's possible to map a second domain to your network, so that instead of having example.com and foo.example.com you have example.com and fooexample.com

In order to do this, you need a plugin called WordPress MU Domain Mapping

Once you activate the plugin, mapping the domain is similar to manually mapping the subdomains.


 * 1) add the domain to you panel
 * 2) have it mirror your main domain

Troubleshooting
If things go wrong, try looking up your problem on the WordPress Support Forum for Multisite. If you can't find an answer, ask it there. Be sure to note the Debugging page for needed information before posting to the forums.


 * Make sure that you have created the domain to work without 'www.' on the domain management page in the panel.
 * Make sure you installed the software without the 'http://www' in the domain name if you are using subdomains.
 * Did you accidentally create a subdomain install unintentionally/without contacting support to create a wildcard? If so, dump your database and start over. (Or ask for the wildcards to be put in place. Then try your site.)
 * If you run into trouble, the first place to look is within the server's error logs. You may find a clue as to what is occuring.
 * Be sure to search the forums with keywords covering your issue. Chances are someone has already run into the issue that you are having.
 * If you are getting errors involving "cgi-system", double-check that your domain is using PHP 5.x. You can change this in your domain panel and it'll switch in about 10 minutes.
 * If you are using the domain mapping feature, you need to configure a unique IP. Otherwise Apache will not recognize the request.