SharePoint 2010: The operation that you are attempting to perform cannot be completed succesfully

Problem

Your web application has a single content database.  You have previously created a granular backup of a site collection in the web application.  You attempt to perform a site collection restore,

Restore-SPSite [site collection URL] -Path [filename] -Force

but then experience the following error:

Restore-SPSite : The operation that you are attempting to perform cannot be completed succesfully.  No content databases in the web application were available to store your site collection.  The existing content databases may have readhed the maximum number of site collections, or be set to read-only, or be offline, or may already contain a copy of this site collection.  Create another content database for the Web application and then try the operation again...

Solution

This can be related to an orphaned site in the database or a database upgrade needed.  But before engaging more complex testing, be sure to check the content database properties:

• Database status: should be set to Ready.
• Number of sites  before a warning is generated: should be set to 2 or greater.
• Maximum number of sites that can be created in this database: set to 3 or greater.

References

• Restore a farm (SharePoint Foundation 2010)
• SharePoint 2010 Restore-SPSite problems
• Orphaned site issue when attempting to backup/restore a SharePoint site collection