Hosting 101 Part 1
Before providing the steps of setting up hosting, it's important to understand the main concepts behind O14 hosting.
SharePoint 2010 has a rich set of hosting features which triumph over the previous version in many ways. It's now simple to setup hosting on the site collection level.
Each tenant would only have full administrator rights on his/her assigned site collection. Customer 2 and users accessing site collection 2 wouldn't be able to access Customer 1's site.
Also, service applications that are in hosting mode would keep each tenants data separate from another tenants. For example, one shared search service application could service customer 1\site collection 1's data and customer 2/site collection 2's data while keeping them separate from each other.
For Example: Users searching in site collection 1 will not be able to search and find content that resides in site collection 2. Users searching in site collection 2 will not be able to search and find content that resides in site collection 1. They will be able to search and locate data within the site collection they are searching from.
The segmentation is possible through the use of site groups also known as site subscriptions. In the example above, customer 1's site collection belongs to site group 1 and customer 2's site collection belongs to site group 2.
Things to know about site groups:
1. Sites can belong to only one site group at a time.
2. Sites cannot join a site group that contains sites that exists on a different web application.
3. A site group can span across more than one content database
4. No GUI interface for managing site groups. PowerShell is required to create/manage/remove site groups.
Tenant Admin Site
A hosted customer is referred to as a tenant. You can provision a tenant admin site which gives the tenant full administrator rights over the site collection. The tenant admin site can be used to create additional sites for example after self service site creation is enabled.
Service Applications and Hosting
Be default, a service application is consumed at the web application level. So all sites, under a web application would consume from the same service application and data would be shared. In hosting mode, a shared service application partitions data where every site group has its own partition. The partition isn't shared meaning other site groups wouldn't be able to see this data even though all sitegroups are using the same service application. Configuring hosted service applications may differ based on the type of service application that is being deployed.
For Example: Deploying a Shared search service application requires you to use PowerShell with addition of -partitioned switch
It's also possible to deploy features in an "a la carte" manner to site groups. So one site group can have more features available than another. This is configurable from PowerShell.
Hosting Part 2 provides a step by step walk though using PowerShell
-Russ Maxwell, MSFT