Administrating the Core Database Engine - Microsoft SQL Server 2008 R2 Administration - page 55

The next step for a database mirroring endpoint requires the encryption of data that is sent
over mirroring connections. In this case, the endpoint can connect only to endpoints that
also use encryption. Database mirroring endpoints support two encryption algorithms— RC4
and AES .
The final step is to ensure that the mirroring endpoint is created and configured correctly. The
verification settings can be accomplished by querying the sys.database_mirroring_
endpoints system catalog view. The following query confirms the name of the endpoint,
the state (whether or not it has started) and other mirroring related attributes:
SELECT d.name, d.database_id, m.mirroring_role_desc,
m.mirroring_state_desc, m.mirroring_safety_level_desc,
m.mirroring_partner_name, m.mirroring_partner_instance,
m.mirroring_witness_name, m.mirroring_witness_state_desc
FROM sys.database_mirroring m JOIN sys.databases d
ON m.database_id = d.database_id
WHERE mirroring_state_desc IS NOT NULL
There's more...
In order to continue the transactions from the primary server to the mirror server, it is ideal
to restore the transaction log backup (which has been taken after the full database backup)
on the mirror server. It is also essential that no transactions should occur on the primary
database until the transaction log is restored on the mirror server.
Restoring a user database doesn't bring along the necessary SQL or Windows logins to the
server containing the mirrored database. Any SQL or Windows logins mapped to database
users in the principal database should also be created on the mirrored SQL Server instance.
These logins should be ready in the event of a failover; when the mirror database takes over
the role as the principal. If the logins are not on the mirror database SQL Server instance, the
database users within the mirrored database will be orphaned (the database users, without
any associated logins will not be able to be access the database).
See Also
For more information on SQL Server Database Mirroring feature enhancement
such as automatic page recovery, refer to the Implementing Database Mirroring
features and performance enhancements section of Chapter 6 , Availability and
Programmability enhancement .