Database MIRRORING in SharePoint 2010 - What to do in absence of Witness server

Hi,

Our environment is divided in 2 DC's, DC1 has our database cluster(2 nodes) and the DC2 has our mirroring server. 

Now as part of DR test, DC1 will be shut down. So our Mirrored server in DC2 should cater all requests. To achieve this, I have set "Failover Server" for our content DBs, service application DBs from Central Admin > Manage Content DB/Service Application. I will set failover server for Config DB using Powershell.  However I DONOT have "witness server" in place.

Now here are the things which I need help on:

1. Once I set "Failover Server" for content DB in Central Admin, where can I see these changes? I mean where is that config file where this change is set?

2. As we do not have a Witness Server, what all steps will be followed manually to achieve this failover?