Consider the following Scenario, You are using SQL Server 2008 Enterprise edition RTM or higher version and you are Transparent database encryption (new feature introduce in SQL Server 2008) to encrypt the Database to be mirrored. The database encryption key has been encrypted using a server certificate and which is turn encrypted using master database key (usually a symmetric key).
When trying to setup database mirror using SSMS you might get the below exception
TITLE: Database Properties
An error occurred while starting mirroring.
Alter failed for Database '<DB_NAME>'. (Microsoft.SqlServer.Smo)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=10.0.1787.0+((Katmai_RTM_QFE-CU).090107-2206+)&EvtSrc=Microsoft.SqlServer.Management.Smo.ExceptionTemplates.FailedOperationExceptionText&EvtID=Alter+Database&LinkId=20476
Alter failed for DatabaseEncryptionKey 'Microsoft.SqlServer.Management.Smo.ObjectKeyBase'. (Microsoft.SqlServer.Smo)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=10.0.1787.0+((Katmai_RTM_QFE-CU).090107-2206+)&EvtSrc=Microsoft.SqlServer.Management.Smo.ExceptionTemplates.FailedOperationExceptionText&EvtID=Alter+DatabaseEncryptionKey&LinkId=20476
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
Database '<DB_NAME>' cannot be opened. It is in the middle of a restore. (Microsoft SQL Server, Error: 927)
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=10.00.1787&EvtSrc=MSSQLServer&EvtID=927&LinkId=20476
It seems to be an issue with SSMS GUI. To workaround this problem you can use T-SQL to setup Database Mirroring in SQL Server 2008 of an encrypted database.
Here, I am going to explain the setup by step procedure on how to encrypt the database using TDE and then mirror the encrypted database using T-SQL.
On the Principal Site
/* Create a Database Master Key in the Master Database which should be secured by a password. If you omit to specify the encryption mechanism (password) while creating the MASTER KEY, the database master key gets encrypted by SERVICE MASTER KEY (default behavior). In that scenario you might need to export the service master key and copy/import it on the mirror site.
Since the database master key is a symmetric key used to protect the private keys of certificates and asymmetric keys that are present in the database.
Information about the database master key is visible in the sys.symmetric_keys catalog view.
If the database master key already exists and not in use or use wants to change the encryption algorithm or key protection mechanism, either you can the alter the database master key or drop and recreate it.
In my Test Scenario, I'm dropping the existing master key and creating a new master key encrypted with password */
--Check if the master key already present.
select * from sys.symmetric_keys
--Drop the existing Master Key
DROP MASTER KEY
--Create Master Key in Master Database
CREATE MASTER KEY ENCRYPTION BY PASSWORD = '<TypeStrongPassword>';
**Note : TypeStrongPassword should remain same throughout the setup.
--Create Server Certificate in the Master Database encrypted with master key (created above) which would be used to create USER database encryption key.
CREATE CERTIFICATE <MyDB_Mirror_Server_Cert> WITH SUBJECT = 'SQL TDE CERT'
*Note : Replace <MyDB_Mirror_Server_Cert> with the name of Certificate. You can specify any name of your choice. Also you can change the SUBJECT to a more meaningful description.
-- Now in the User database, create a Database Encryption Key. In my test scenario, I'm dropping the existing Database Encryption Key if already exist and not in use.
-- Information about the database encryption keys is stored in sys.dm_database_encryption_keys.
USE <User Database>
DROP DATABASE ENCRYPTION KEY
CREATE DATABASE ENCRYPTION KEY
WITH ALGORITHM = AES_128
ENCRYPTION BY SERVER CERTIFICATE <MyDB_Mirror_Server_Cert>
--Enabling Transparent Database Encryption for the USER Database
ALTER DATABASE <User Database> SET ENCRYPTION ON
-- Now Backup master key immediately
OPEN MASTER KEY DECRYPTION BY PASSWORD = '<TypeStrongPassword>';
BACKUP MASTER KEY TO FILE = '<Full path and exportmasterkey filename>’
ENCRYPTION BY PASSWORD = '<TypeStrongPassword>';
**Note: Replace <Full path and exportmasterkey filename> with full path and export file name. Also Replace <TypeStrongPassword> with the actual password use to encrypt the master key.
-- Now Backup Server certificate as well
BACKUP CERTIFICATE <MyDB_Mirror_Server_Cert> TO FILE = '<Full path and export cert filename>'
WITH PRIVATE KEY ( FILE = '<Full path and export filename _key>' ,
ENCRYPTION BY PASSWORD = '<TypeStrongPassword>');
-- Perform Full database backup of the Principal database
On the Mirrored Site
/* On Mirror Server, restore the master key from backup performed from principal site. Since the database master key is a symmetric key used to protect the private keys of certificates and asymmetric keys that are present in the database. Information about the database master key is visible in the sys.symmetric_keys catalog view.
If the database master key already exists and not in use, drop the existing database master key (if any) and restore it from backup taken from principal site.
In my Test Scenario, I'm dropping the existing master key and restoring the master key from backup taken from principal site */
drop master key
RESTORE MASTER KEY
FROM FILE = ' Full path and exportmasterkey filename>'
DECRYPTION BY PASSWORD = '<TypeStrongPassword>'
-- Create server certificate on the mirror site using the PRIVATE KEY backed up from principal site
DROP CERTIFICATE <MyDB_Mirror_Server_Cert>
OPEN MASTER KEY DECRYPTION BY PASSWORD = '<TypeStrongPassword>'
CREATE CERTIFICATE <MyDB_Mirror_Server_Cert>
FROM FILE = '<Full path and export cert filename>'
WITH PRIVATE KEY (FILE = '<Full path and export filename _key>',
DECRYPTION BY PASSWORD = '<TypeStrongPassword>');
-- Restore the database from backup with NORECOVERY
RESTORE DATABASE <User Database>
FROM disk = 'C:\Program Files\Microsoft SQL Server\MSSQL10.x\MSSQL\Backup\<Backup_FileName>.bak'
MOVE '<Primary FileGroup>' TO
'C:\Program Files\Microsoft SQL Server\MSSQL10.y\MSSQL\DATA\<PrimaryDB_File>.mdf',
MOVE '<Logical File name of LogFile>'
TO 'C:\Program Files\Microsoft SQL Server\MSSQL10.y\MSSQL\DATA\<Log_File>.ldf'
Where x = Instance ID of the Principle Server and y = Instance ID of Mirror Server
-- On the Mirrored Site, drop the existing mirroring endpoint and create the database mirroring endpoint as follows
DROP ENDPOINT <endpoint_mirroring>
CREATE ENDPOINT <endpoint_mirroring>
STATE = STARTED
AS TCP ( LISTENER_PORT = 7023 )
FOR DATABASE_MIRRORING (ROLE=PARTNER);
-- Verify that the endpoint is properly configured and is in state "STARTED"
select * from sys.database_mirroring_endpoints
--On the primary site, drop the existing mirroring endpoint and create the database mirroring endpoint as follows
AS TCP ( LISTENER_PORT = 7022 )
-- First set the principal server as partner on the mirror database
ALTER DATABASE <User Database> SET PARTNER = 'TCP://<FQDN of the Principal Server>:7022'
-- Now set the Mirror server as partner on the principal database
ALTER DATABASE <User Database> SET PARTNER = 'TCP://<FQDN of the Mirror Server>:7023'
Now the DATABASE Mirroring has been successfully setup when using Transparent Data Encryption in SQL Server 2008.
You can test and verify failover works fine either using SSMS or the T-SQL command.
Tech Lead, Microsoft SQL Server
Tech Lead, Microsoft SQL Server
PingBack from http://blog.a-foton.ru/index.php/2009/03/31/setting-up-database-mirroring-in-sql-server-2008-using-t-sql-when-the-database-is-encrypted-using-transparent-data-encryption/
Thank you for the instructions above.
At the final step:
(-- Now set the Mirror server as partner on the principal database)
I receive the following error:
Database mirroring error: status 15581, severity 16, state 0, string <database name>
Do you know what causes this as everything up to that final point works correctly. Thank You.
Since the database on the principal site is encrypted state.
1) check if you have opened the master key and the other key(s) (if any) you are using in TDE before issuing the Alter database statement on the principal site
2) Also check the state of the Mirroring endpoint, it must be in state "STARTED".
I would like to THANK YOU for detailed step by step instructions above. It really worked for me, not only saved my time but made my life easy.
Once again thank you very much. you guys really ROCK...!
This is a good post. I have a question, how to find which is mirrored database or principal database using TSql command?
I have this exact situation with a few differences.
I have another database mirrored that doesent need TDE. I have that mirrored just fine.
When I run the
ALTER DATABASE <User Database> SET PARTNER = 'TCP://<FQDN of the Principal Server>:5022'
I get Error
Msg 1416, Level 16, State 31, Line 1
Database "Database" is not configured for database mirroring.
Or through the GUI I get the usual error.
I have used the same script to create the mirroring for the other database. And it runs.
Help is very welcome!
Error 1416 : states that the mirror database has been recovered. Ensure that the mirrored database must be in Restoring state (NORECOVERY option)
Run the below queries on the mirror server and verify the state
--check the mirroring endpoint state
select dme.endpoint_id, dme.name, dme.principal_id, dme.state_desc,
dme.role_desc,dme.connection_auth_desc,dme.certificate_id, dme.encryption_algorithm_desc, te.port, te. ip_address
from sys.database_mirroring_endpoints dme inner join sys.tcp_endpoints te on dme.endpoint_id = te.endpoint_id and te.type = 4
-- check the mirror database state
select database_id, user_access_desc, state_desc, recovery_model_desc, is_broker_enabled, log_reuse_wait_desc
from sys.databases where name = '<database_name>'
In case, the mirror database is in ONLINE state, you need to again restore the database and the subsequent T-Log backups with NORECOVERY option before setting the mirroring partners
Thanks for the reply,
I have verified all of this info. Restored the database with NORECOVERY and T-Logs with NORECOVERY.
The database on the mirror says (Restoring....)
I have 3 other mirrored databases on these servers without TDE and they work fine. For setting up mirroring I have just run the script to ensure I am exicuting it the correct way.
Still unsure of next steps.
I appreciate the detailed explanation of how to Mirror Encrypted databases.
However, I am experiencing the same Database mirroring error that Jeff Strongo reported back on April 20:
status 15581, severity 16, state 0, string <database name>
I have checked the two items you gave in your follow-up email, but this has not cleared the error for me.
I wondered whether any other information has surfaced about this error ?
Appreciate any other information that you have.
Provide details of your environment in which you are trying to setup DB Mirroring with TDE database which includes the following:
1) SQL Server build of both the prinicipal and the mirrored Server
2) Are both the Servers in same subnet / same domain
3) Is there any firewall between these two servers.
4) which step of the above script fails and with what error.
5) how the database is encrypted, provide some details of encryption hierarchy being used.
6) Are you using same both in both the mirroring endpoints or different ports. Also ensure that the port(s) are open in the firewall or the Antivirus settings (if any).
7) have you verified if the mirroring endpoints are working fine or not.
Sorry for my slow response to your questions. I've been working on other projects in the meantime.
2) Both servers are in the same subnet/domain
3) No firewall between servers
4) Final step. Error is: status 15581, severity 16, state 0, string <database name>
5) Database is encrypted using the exact instructions in your article
6) Both endpoints are 5022 (please note that mirroring of non-encrypted db works fine)
7) Mirroring end points are STARTED.
I worked with Microsoft support to resolve my issue (REG:109103045827330).
For mirroring to work for me, the following extra statements needed to be executed immediately after the Master Key was restored on the Mirror site:
OPEN MASTER KEY DECRYPTION BY PASSWORD = '<strong password>'
ALTER MASTER KEY ADD ENCRYPTION BY SERVICE MASTER KEY
This was the only change that I needed to make to your instructions to fully resolve the "status 15581" error I was receiving.
here is another trick,configure mirroring first, then implemente TDE encryption:
1. configure database mirroring first
2. create master key on principal
3. create certificate on principal
4. suspend the mirroring between principal and mirroring server
5.don't resotre the master key to mirroring server, just create a master key on mirroring server, restore the certificate from principal server
6. resume the mirroring between database.
It works for me, if I restore the master key to mirroring server,run
will get Error
Thank you for your comments!