Here’s my stripped-down set of steps for converting individual WordPress installations to a single Multisite installation. Read the full article with commentary for a good laugh at my expense.
I assembled the following list of steps by capturing individual tasks from multiple articles on sticky notes as I researched. Then I arranged the steps into a more-or-less logical order.
I’m sure there are missing steps and a better order to do them in, so feedback to improve these instructions is welcome.
Steps To Migrate to WordPress Multisite
- Identify what problems you are trying to solve.
- Determine if WPMU will solve those problems.
- Check out alternatives to Multisite as part of due diligence.
- Do an inventory of your sites to see whether and how many efficiencies can be realized, i.e. is it worth the effort. My inventory looks like this:
- Confirm whether there are WPMU-compatible versions of the plugins and themes you want to use.
- Understand the basic steps involved in migrating to WPMU. Ask:
- Am I technically capable of doing those things?
- Do I have the necessary tools and access to do those things?
- Can I get help if I get stuck?
- Am I fine with sites being down for awhile if I get stuck?
- Am I fine with starting over from scratch in case something goes horribly, terribly, disastrously wrong?
- Does my web hosting service support WPMU?
- If yes to all of the above, then carry on.
- Do a deeper read of any steps specific to your situation.
- For example, find out if your sites need to have different IP addresses for whatever reason (for example SEO). (WPMU doesn’t seamlessly support this.)
- Decide on subdomain vs. folder configuration. (Default for converting existing site is subdomain.)
- Write down or screenshot any plugin settings needed.
- Create a wildcard sub domain via your web host.
- Delete quarantined spam comments — no need to bring those forward.
- Use https://sucuri.net/ to ensure your site hasn’t been hacked or infected before backing everything up.
- Back up everything.
- Disable plugins so they can’t interfere with the migration except for whatever plugin you may be using to export.
- Export contents of each WordPress install using either a plugin or native WP Export (Tools > Export) to create and/or verify a WXR and/or an XML file.
- Edit the wp-config file per instructions to activate Multisite.
- Use Tools > Network Setup > Install Multisite.
- Backup then add lines to wp-config and .htaccess files per instructions.
- Clear the cache and cookies.
- Log in again.
- Go to My Sites > Network Admin > Sites > Add New.
- Create subsite1.mainsite.com and any other subsites you need.
- Decide on a default theme until the others get installed (I used Twenty-Seventeen).
- Install themes used by sites (MU compatible versions) > Network Enable.
- Install plugins used by sites (MU compatible) > Network Enable.
- Delete dummy content, comments and widgets to get empty sites.
- Install WordPress Importer plugin > Network Enable.
- Import XML files (Tools > Import > WP > Run) into the appropriate subsites.
- Choose how to handle imported users and post assignments.
- Choose to download and import attachments.
- Check to see that everything got imported correctly.
- Map domain names to their new sites using native WP domain name hookup or WP MU Domain Mapping plugin. (Sorry, I don’t have better instructions here because I didn’t do it correctly myself.)
- Uninstall any plugins used for the migration that are no longer needed.
- Clean up any backup or temporary files used during the migration
- Uninstall the separate WP installations
- Check that all is well after doing that.
- Go through “hardening WP” steps to secure your sites.
- Clean up extra users for each site and change passwords for them.
- Log into each website’s dashboard and make sure all is in order.
A few of the many, many, many helpful resources I consulted:
- Before You Create A Network – WordPress Codex
- Taylor McCaslin: Best Friend or Worst Enemy – Multisite Do’s and Don’ts (video)
- 7 Tools To Manage Multiple Sites From Single Dashboard
- The Ultimate Guide to WordPress Multisite
- The Ultimate Guide to Domain Mapping with WordPress and Multisite
- WordPress Security: The Ultimate Guide
WordPress sticker image courtesy of wpmxday on Flickr / hiveminer.com