Multisite Upgrade Structure

Hi there,

I currently have a number of sites, each with an existing WordPress installation. They are found at:

example.com
sub1.example.com
sub2.example.com
etc.

I want to move over to a Multisite installation. All subdomain sites look and feel the same (same theme and setup) but the root site is totally different. I am unsure about the best and safest way to proceed in upgrading (/ replacing) my current network to a Multisite install.

I’m pretty unsure about the best path to take, and any help would be much appreciated. I don’t mind taking sites down for maintenance but I need to preserve the current site files and content so they can be added to the new network sites.

The options I have come up with are:

1. Upgrade the existing WP installation in the root domain (example.com) to enable multisite.

• Will this work properly with a complex WP site at example.com?
• How do I manage subdomain mapping given that there are already installations of WP in each subdomain? (This applies to the other options too.)

2. Leave the root installation as it is. Install a new WP with Multisite in a different directory (example.com/multi). Run the subdomain sites from this installation.

3. Install a new WP with Multisite in a different directory (example.com/multi) and run all sites, including example.com, from this installation.

• If I do this, which seems ideal, how do I manage the transition on root and subdomains without losing files, content or settings?

As you can see, I’m really looking for the best way to bring all my sites together under a Multisite with a smooth transition, without losing any content.

Thanks in advance for your help!