When failing over to a SQL Mirrored Database, the Provisioning Server shows offline and is unable to connect.
Install the SQL Server Native Client on all the Provisioning Services servers.
If you are using Database Mirroring feature, then the SQL native client is required on the server. If this client does not already exist, the option to install SQLncx64 or SQLncx32 is presented when the product software is installed.
Complete the following to verify if you are missing SQL native client:
Click the Drivers tab. SQL Server Native Client should be listed, as displayed in the following screen shot.