Hosting Environment Requirements on WordPress
Before you enable the WordPress multisite feature, you need to determine whether you plan to manage just a few of your own WordPress blogs or websites, or run a full-blown blogging network with several hundred different blogs and multiple users.
If you are planning to run just a few of your own sites with the WordPress multisite feature, then your current hosting situation is probably fine. However, if you plan to host a large network with hundreds of blogs and multiple users, you should consider contacting your host and increasing your bandwidth and disk space.
Small blogging communities can be easily handled using a shared-server solution; whereas larger, more active communities should really consider a dedicated-server solution for operation. The difference between the two lies in their names:
Shared-server solution: You have one account on one server that has several other accounts on it. Think of this as apartment living.
Dedicated-server solution: You have one account. You have one server. That server is dedicated to your account, and your account is dedicated to the server.
A dedicated-server solution is a more expensive investment for your blog community, while a shared-server solution is the most economical. Your decision on which solution to go with for your WordPress Network blogging community will be based on your realistic estimates of how big and how active your community will be. You can move from a shared-server solution to a dedicated-server solution if your community gets larger than you expected; however, starting with the right solution for your community from day one is easier.
The WordPress network feature gives you two different ways to run a network of blogs on your domain. You can use the subdomain option or the subdirectory option. The most popular option (and recommended structure) sets up subdomains for the blogs created by your WordPress Network. With the subdomain option, the username of the blog appears first, followed by your domain name. With the subdirectory option, your domain name appears first, followed by the username of the blog. Which one should you choose? The choice is yours. You can see the difference in the URLs of these two options by comparing the following examples.
A network of sites works best on a LAMP (Linux, Apache, MySQL, and PHP) server with the mod_rewrite Apache module enabled. Mod_rewrite is an Apache module that builds URLs that are easier to read. In WordPress, this is used for permalinks. If your install uses any permalink other than the default, ?p=123, then you’re okay. Your web host can help you determine if your web server allows this. It is a requirement for setting up the WordPress multisite feature.
Subdomain sites work by way of a virtual host entry in Apache, also known as a wildcard subdomain. On shared hosts, your web hosting provider support team will have to enable this for you, or they may already have done so for all accounts. It is best to ask your hosting provider before you begin. In these situations, the domain you use for your install must be the default domain in your account. Otherwise, the URLs of your subsites will fail to work properly or to have a folder name in the URL.
Before proceeding with the final steps in enabling the WordPress multisite feature, you need to get a few items in order on your web server, like editing and configuring Apache server files. If you can, perform the configurations yourself. If you don’t know how, are uncomfortable with adjusting these settings, or don’t have access to change the configurations in your web server software, you need to ask your hosting provider for help or hire a consultant to perform the configurations for you. Web hosting providers have support staff to help you with these things, if you need it — take advantage of that!