Multiple My Site Hosts

Question

I have a scenario where two sub-companies of a company should be deemed independent and as such need to not share any of the following

1. Search - Should not rely on security trimming User
2. Profiles / My Site - users my sites for sub-company a should not be visible to sub-company b users.
3. Web Applications / Site Collections - each sub-company should have its own intranet and document management.

Item 3 is nice and easy regardless of what is selected to be able to carry out 1 and 2.

In theory I could create multiple search scopes for Item 1 but really I'd prefer not to have to manage scopes for each web application

Having my sites only available to members of your own subcompany is a problem to me.

Can I have two my site hosts so that the team site host and intranet for subcompany a is directed to one my site host and the team site host and intranet for subcompany b is directed to a different my site host?

If the solution is to create multiple web applications for each subcompany in a multi-tenancy environment, can I then convert an existing farm to a multi-tenanted one without uninstalling SharePoint?

The finished solution should allow users of subcompany a to access their sites as follows

• http://profiles.subcompanyA.local
• http://intranet.subcompanyA.local
• http://teams.subcompanyA.local

And subCompany B:

• http://profiles.subcompanyB.local
• http://intranet.subcompanyB.local
• http://teams.subcompanyB.local

The teams and intranet sites will have drastically different structures.

Answer 1

You can create mult-tenant aware web application and service applications within your existing farm (it will coexist with your current configuration). However, before proceeding down that route, you need to understand the limitations and be sure it really fits your needs (and you can support it).

If all users are part of the same forest / domain, you can still use a normal farm.

1. Separate Web Applications
2. 2 Search Service Applications (this may not be required due to native security trimming, as long as your groups are completely separate, or via custom scopes as you listed above).
3. You can only have one My Site host per user profile application. All the separation stuff you want to do is done via the User Profile Sync Service (limit user search to OU, filters, etc), and you can only have one of these assigned to a server. So you can create a second UPS / UPA as long as it is running on a separate server. Then you can allocate your my site hosts per UPA, and have the UPS locked down to only certain users.

You will also need to configure your proxy groups so the correct services are assigned to the correct web applications. Note, you can have other duplicate service applications as required as well.

Your web.config files will require some additional settings to trim people picker as well.

Answer 2

You absolutely can covert to a Multi-tenant solution. It is not part of the sharepoint install so you can convert anytime. Here is a good overview: http://www.harbar.net/articles/sp2010mt1.aspx

And here is a brief overview of setting up subscriptions using powershell and how to add existing site collections to a subscription structure : http://blogs.technet.com/b/speschka/archive/2009/11/30/enabling-multi-tenant-support-in-sharepoint-2010.aspx

Realize however that once you've added a subscription to a site that action cannot be undone. And living in a Multi tenancy environment adds to the admin overhead