If you're a professional WordPress site builder with a sizable number of blogs to maintain, you've probably wondered – if only once – how much better your life would be if you could access all of this arsenal. from a single dashboard. WordPress answers this concern in the affirmative via this definition  codex  :

Multisite is a feature of WordPress 3.0 and later versions that allow multiple virtual sites to share a single WordPress installation. When the multisite feature is activated, the original WordPress site can be converted to a network of sites

That is, a feature of WordPress 3.0 and future versions that allows multiple virtual sites to share a single WordPress installation. When multisite functionality is enabled, the original WordPress site is used for managing the site network. In this article, I'll explain how to install and administer WordPress in multisite mode.

This type of configuration can be useful if you want to give your members the possibility to create their own blog from yours (ex. wordpress.com with no less than 37 million sites), if you or your agency maintain sites for customers, or for personal needs as a developer or administrator WordPress.

Before going into details, in this talk, I will use the term

  • network to designate all the sites of the installation in multisite mode. Although it is called a network of sites, the sites it contains do not communicate with each other as in other types of networks.
  • website for a single site in the network and
  • main site for the site from which you manage your network.

I would also like to assure you that if you know how to install and administer a WordPress site then you will know how to install and administer a network with a few features.

Differences between standard installation and multisite installation

I would like to point out to you 3 differences between these two types of installations:

The dashboard : When multisite mode is activated, new features are added here and there in the dashboard.

multi-dashbord

The file wp-config.php and the repertoire wp-upload : additional lines of codes will be added to the file wp-config.php in order to activate the multisite mode and informed WordPress accordingly. The directory wp-upload will contain a directory for each site created, with the name of the identifier of this site. All files uploaded for this site will be contained in its directory.

The database : Even if you don't necessarily need to know it, be aware that a normal WordPress installation has 11 tables in its database. For a multisite configuration, in order to separate the content of each site, 9 of these tables will be duplicated for each site created within the network.

Some considerations before activating multisite mode

In general, if you find yourself in any of the following situations, please reconsider your multisite needs:

  • You don't need more than one site
  • Your sites are hosted separately at different hosts
  • Your sites can not share the same database
  • Your sites will have different IP addresses
  • Site administrators will have the right to install their own plugins and themes
  • You will need to migrate your network to another host (it is possible to do, but to avoid)
  • Your serveraccommodation do not respect the required characteristics
  • You do not have write access to your server

Enable multisite WordPress

 Now that you know what multisite mode is, in which scenarios to use it or not, let's get down to business.

The procedure for installing a WordPress site in multisite mode does not differ very much from that of a standard site. It is during the activation that a few additional, simple to perform steps are necessary. And depending on your case two procedures are to be considered:

Enabling multisite on a new WordPress Installation

The first thing is toInstall WordPress as you are used to doing.

When it's done, open your file wp-config.php and locate the line:

/* C'est tout, ne touchez pas à ce qui suit ! Bon blogging ! */

Just above, add this:

define( 'WP_ALLOW_MULTISITE', true );

which has the effect of informing WordPress that you want to use multisite mode. Save your file wp-config.php. Now you need to install it.

In your dashboard, go to Tools> Network creation. There, you will have to choose between URLs with subdomains (eg site1.mynetwork.com) and URLs with subdirectories (eg mynetwork/site1). Choose what best suits your case. complete the rest of the online form And click install to go to the installation page.

activation-multisite

Rendering this page, follow the instructions file modification wp-config et .htaccess save the files and click on the link to log in. Once logged in, you will see your multisite dashboard.

Enabling multisite on an existing installation

To activate multisite on an existing installation, the procedure is the same except that you cannot choose between sub-domains and sub-directories. In addition if your site is more than a month old, the mandatory configuration will be in subdomains.

Administration of the sites of the network of sites

This activity consists more or less in 4 tasks:

Website creation

To create a site, from the WordPress toolbar, go to My sites> Network admin. Then Sites> Add. You will see the online form site creation:

website-creation-form

Fill it out and click Add Site. The site will be created and you will see the list of your sites in Sites> All sites.

multi-site-list

You notice that I have two sites site1 et site2 (in subdirectories) in my network Multipress.

Install and activate themes

This is where the rules change slightly. In a multisite configuration, a theme can only be installed by the network administrator, ie you. It is available in a site, if it is enabled for that site or if it is enabled for the entire network.

To activate a theme on the whole network, go to Themes> Installed themes and click the link Enable on the network which is below the topic concerned.

However, to activate a theme on a single site, go to Sites> All sites. On the list of sites, click Edit that appears when you hover over the name of the relevant site.

It is in this page that you configure what relates to this site, in other words its administration page. Choose tab Themes: to see the list of themes available for this site. Then click on the link Enable of the chosen theme.

Site-theme-list

When you go to this site's dashboard (in my case, WordPress Toolbar: My sites> SITE 1> DashboardThen Appearances> Themes) you see the newly activated theme for the siteinstalled-themes.

Install and activate plugins

Here, too, the rules change. You, as administrator of the site network, are the only one authorized to install the plugins. Even site administrators do not have this privilege. They can only activate and deactivate plugins. You can activate a plugin network-wide, but you can't do it just for one site. However, you can install it, and decide to activate it on a particular site.

Activating a plugin on the whole network is very easy. In the main site dashboard, go to Extensions> Add, install the plugin as you always have. When the plugin is installed, click Enable on the network.

Unlike that of a theme, activating a plugin on a site is slightly more elaborate. See you in Extensions> Add Of the main site's dashboard, install the plugin, but this time, click on the link Return to Extensions page. Now on the dashboard of the site on which you want to activate the plugin appointment in Extensions and click the link Enable Which is under the name of the plugin.

Site Administration

Remember, when we installed a theme, we went to its administration page via Main Dashboard> Sites> 'modify site'. I propose you to review the other 3 tabs (Info, Users and Settings) on this page.

Info gives general information about the site. In this tab, you can change the site address or its status.

Users lists all the users of the site, these being first of all network users. As network administrator you can use this tab to add or remove users from a site, if they have been previously registered on the network and change the role of site users. The site administrator can add users to the users section of his site, even if they have not previously been registered on the network.

Settings gives you as the network administrator all site configuration options. The site administrator can only see a subset of it via the section Settings Of its dashboard.

Site Network Administration

You now know how to take care of the sites that make up your network of sites. You must now learn how to maintain this network. This activity, which at first glance seems overwhelming, is nothing very complicated and consists of updating WordPress, plugins and themes, managing users and customizing network settings.

Updates in a network of sites

As usual, if WordPress detects an update, whether for a plugin or a theme, you will receive a notification. You will proceed with the update as you normally would. WordPress updates are done in two stages. You update the network first, then the sites that make it up.

Network User Management

As I said before, nothing very complicated here. The Users page shows a list of all users on your network including those that site administrators have added and those who have registered with their sites. What is not common is that you can see which site a user has access to. You still have the ability to edit and delete them. As a network administrator, you can only add a user to a site from that site's users page.

multi-users

Customizing network settings

As you can see in the image below, in this page you customize the operation and use of your network.

settings-multisite

Conclusion

You've seen how to enable the multisite mode of WordPress and how useful it is for some website administrators who have to manage a large number of sites.

Contrary to what you might think, activating WordPress multisite is very easy. It only takes a few extra steps to the standard installation procedure. Also, new pages are added to the dashboard while remaining familiar, so as not to lose users.

To revive you in the knowledge and control of multisite, you can improve your multisite installation with these plugins.