I recently discussed a topic oh having a separate user for each WP database installation which increases safety, and WP MU came up. I believe Conor recommended it.

Since I don't know much about it, I was wondering since I already have multiple installations of WP on my server can it be installed to control those already installed WPs?

Some side info would be nice as well.

Thanks!

Well, as long as none of the tables in your DBs clash, I don't see how this can create problems for you/

As long as there is not any collision you can install it.

I've not tried it but as the others say, it could be worth a shot. From what I remember in my MU testing the program was separate from the standard WordPress installations. I'd say that when I get time I'll test it out and see what I can come up with, but with the rate of how things are going here for me on my end, it could be after the month at this stage. Holiday time has us busy with eCommerce sites and keeping everyone happy.

And what clash might that be? I'm not very DB savvy so if you have the time and will, please elaborate.

Yeah I believe you. I already delayed implementation of MU myself because of my busy schedule.

I've just tried it out thoroughly and I've realized that WP blogs can be created only on subdomains and subfolders. Blogs can't be mapped on domains by default, which is what I need. I've found a plugin that will enable that. I'll let you know how it goes.

I must be misreading this, because I've not found this to be true.

Of course WP can be installed anywhere, but with using WP MU you must choose between 2 options during installation: subdomains and subfolders. I just said that WPMU can't map WP blogs, that it controls, on domains. But there is a plugin to make WPMU map new blogs to domains.

In my personal opinion, it's not worth it. If perhaps plugin loses the support you'll be stuck with big community of created blogs that can't be transferred to subdomains of subfolders.

Thanks for the explanation - I knew I was missing something in the translation.

Well, I guess that WPMU is not very versatile solution unless you need a scenario that is exactly the same as wordpress.com where people can register their own blogs, for example, blog1.wordpress.com, blog2.wordpress.com, and so on.

http://www.ninjablogsetup.com
http://codex.wordpress.org/Installing_WordPress
here you get proper solution.

Well, WPMU can not be used to control the existing blogs but a way exists if you do not want to have multiple installations running along with WPMU.

What you can do is, simply export the xml of those seperate WP blogs and import them into WMPU's blog (a new blog either on sub-domain or sub-directory). Then you can remove the existing installations without any lose. [Being on the safe end, keep the backup of DB and xml until you get the blog running under WPMU]

Your concern about the plugin is right in place and it as word of caution too.