Order of Installing Service Pack on systems hosting Database Mirroring

If you have servers which hosts database mirroring and you want to install the service pack on those systems and you are trying to find out the order in which you need to do it then, here is the order in which you need to install service pack or a hotfix on the systems which hosts Database Mirroring.

1. Backup the principal
2. If you are using a witness, remove it from mirroring
3. Upgrade the mirror
4. Failover to mirror
5. Upgrade original principal/current mirror
6. If you wish to fail back to original principal continue on; otherwise, proceed to step 8
7. Failover to original principal
8. If you are using a witness, add it back into mirroring

For more information refer to the following article to know the entire process for upgrading both the principal and mirror servers.
http://technet.microsoft.com/en-us/library/bb497962(SQL.90).aspx

Error while starting SQL Server Agent in Denali (OpenSQLServerInstanceRegKey:GetRegKeyAccessMask failed (reason: 2).)

I had recently installed SQL Server 2012 AKA Denali CTP version on my system and when I tried to start the SQL Server agent, The agent was starting and was immediately getting stopped by displaying the below message.

When I investigated further, I found the below error message from the event viewer.

OpenSQLServerInstanceRegKey:GetRegKeyAccessMask failed (reason: 2).

Possible Workaround:

I got this working by changing the Log on account of SQL server agent from "NT SERVICE\SQLServerAgent" to "Local System" or a domain account.

Recycle error log and SQL Server agent error log (SQLAgent.out) file

Recycle Error log:
When we run the below command, it Closes the current error log file and cycles the error log extension numbers just like a server restart.
Permission Required: sysadmin fixed server role

USE msdb 
GO
EXEC sp_cycle_errorlog
GO

Recycle SQL Server Agent error log (SQLAgent.out):
When we run the below command, it Closes the current SQL Server Agent error log file and cycles the SQL Server Agent error log extension numbers just like a server restart.
Permission Required: sysadmin fixed server role

USE msdb 
GO
EXEC dbo.sp_cycle_agent_errorlog 
GO

Three new DMV's "sys.dm_server_services", "sys.dm_server_registry" and "sys.dm_server_memory_dumps"

The DMV's "sys.dm_server_services", "sys.dm_server_registry" and "sys.dm_server_memory_dumps" are the 3 new DMV's that were introduced in SQL Server 2008 R2 and have been enhanced in SQL Server 2012 AKA Denali.


sys.dm_server_services 
This DMV gives information and status of the services SQL Server, SQL Server Agent and SQL Full-text Filter Daemon Launcher
Usage:

SELECT * FROM sys.dm_server_services

Result:

Reference:
http://msdn.microsoft.com/en-us/library/hh204542.aspx


sys.dm_server_registry
This DMV gives information about installation and configuration data that is stored in the windows registry for the current instance of SQL server.
Usage:

SELECT * FROM sys.dm_server_registry

Result:

Reference:
http://msdn.microsoft.com/en-us/library/hh204561.aspx


sys.dm_server_memory_dumps
This DMV gives information about memory dump files generated by the SQL Server database engine.
Usage:

SELECT * FROM sys.dm_server_memory_dumps

Result:

There are no dump files created yet from my Database engine.
Reference: http://technet.microsoft.com/en-us/library/hh204543.aspx

Get SQL Server details using T-SQL

Here is a T-SQL script which gives you the details of a SQL Server.
This will be very useful when you are gathering SQL Server information from multiple servers and works for SQL Server 2005 and above.

CREATE TABLE #ServerDetails(ID int,  Name  sysname, Internal_Value int, Value nvarchar(512))
INSERT #ServerDetails EXEC master.dbo.xp_msver

DECLARE @InstanceName nvarchar(50)
DECLARE @value VARCHAR(100)
DECLARE @RegKey_InstanceName nvarchar(500)
DECLARE @RegKey nvarchar(500)
DECLARE @AuditLevel int
DECLARE @DataDirectory nvarchar(500)
DECLARE @LogDirectory nvarchar(500)
DECLARE @BackupDirectory nvarchar(500)

SET @InstanceName=CONVERT(nVARCHAR,isnull(SERVERPROPERTY('INSTANCENAME'),
'MSSQLSERVER'))

if(SELECT Convert(varchar(1),(SERVERPROPERTY('ProductVersion'))))<>8
BEGIN
SET @RegKey_InstanceName='SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL'

EXECUTE xp_regread
  @rootkey = 'HKEY_LOCAL_MACHINE',
  @key = @RegKey_InstanceName,
  @value_name = @InstanceName,
  @value = @value OUTPUT

SET @RegKey='SOFTWARE\Microsoft\Microsoft SQL Server\'+@value+'\MSSQLServer\'

    
EXEC master..xp_regread 
  @rootkey='HKEY_LOCAL_MACHINE',
  @key=@RegKey,
  @value_name='AuditLevel',
  @value=@AuditLevel OUTPUT

EXEC master..xp_regread 
  @rootkey='HKEY_LOCAL_MACHINE',
  @key=@RegKey,
  @value_name='DefaultData',
  @value=@DataDirectory OUTPUT

EXEC master..xp_regread 
  @rootkey='HKEY_LOCAL_MACHINE',
  @key=@RegKey,
  @value_name='DefaultLog',
  @value=@LogDirectory OUTPUT

EXEC master..xp_regread 
  @rootkey='HKEY_LOCAL_MACHINE',
  @key=@RegKey,
  @value_name='BackupDirectory',
  @value=@BackupDirectory OUTPUT

END

SELECT  SERVERPROPERTY('ComputerNamePhysicalNetBIOS') [Machine Name]
    ,SERVERPROPERTY('ServerName') AS [SQL Server Name]
    ,SERVERPROPERTY('InstanceName') AS [Instance Name]
    ,SERVERPROPERTY('Collation') AS [Server Collation]
    ,'Microsoft SQL Server ' + CAST(SERVERPROPERTY('Edition') AS varchar(250)) AS Edition
    ,SERVERPROPERTY('ProductLevel') AS [Product Level]
    ,(SELECT Value FROM #ServerDetails WHERE Name = N'Language') AS [Language]
    ,(SELECT Value FROM #ServerDetails WHERE Name = N'Platform') AS [Platform]
    ,(SELECT 'Microsoft Windows NT ' + Value from #ServerDetails where Name = N'WindowsVersion') AS [Operating System]
    ,(SELECT Internal_Value FROM #ServerDetails WHERE Name = N'ProcessorCount') AS [Processors]
    ,(SELECT CAST(Internal_Value AS varchar)+ ' (MB)' FROM #ServerDetails WHERE Name = N'PhysicalMemory') AS Memory
    , CASE WHEN SERVERPROPERTY('IsClustered') = 1 THEN 'True' ELSE 'False' END AS IsClustered
    ,(SELECT value from sys.configurations where name='min server memory (MB)') AS 'Min Server Memory (MB)'
    ,(SELECT value from sys.configurations where name='max server memory (MB)') AS 'Max Server Memory (MB)'
    ,(SELECT CASE WHEN value=0 THEN 'True' ELSE 'False' END from sys.configurations where name='affinity mask') AS 'Automatically set processor affinity mask for all processor'
    ,(SELECT CASE WHEN value=0 THEN 'True' ELSE 'False' END from sys.configurations where name='affinity I/O mask') AS 'Automatically set I/O affinity mask for all processor'
    ,CASE WHEN SERVERPROPERTY('IsIntegratedSecurityOnly')= 1 THEN 'Windows Authentication Mode' 
    WHEN SERVERPROPERTY('IsIntegratedSecurityOnly')= 0 THEN 'SQL Server and Windows Authentication Mode' END AS [Server Authentication]
    ,CASE WHEN @AuditLevel = 0 THEN 'None' 
    WHEN @AuditLevel = 1 THEN 'Successful Logins Only'
    WHEN @AuditLevel = 2 THEN 'Failed Logins Only'
    WHEN @AuditLevel = 3 THEN 'Both Failed and Successful Logins'
    END AS [Audit Level]
    ,(select CASE WHEN value = 0 THEN 'False' WHEN value = 1 THEN 'True' END from sys.configurations where name='remote access') AS 'Allow remote connections to this Server'
    ,(select CASE WHEN value = 0 THEN 'unlimited' ELSE value END from sys.configurations where name='user connections') AS 'Max number of concurrent Connections'
    ,(select CASE WHEN value = 0 THEN 'No Timeout' ELSE value END from sys.configurations where name='remote query timeout (s)') AS 'Query Timeout (s)'
    ,(select CASE WHEN value = 0 THEN 'False' WHEN value = 1 THEN 'True' END from sys.configurations where name='remote access') AS 'Allow Remote Connections to this server'
    ,@DataDirectory AS 'Default Data Directory'
    ,@LogDirectory AS 'Default Log Directory'
    ,@BackupDirectory AS 'Default Backup Directory'
    ,(SELECT value from sys.configurations WHERE name='max degree of parallelism') AS 'Max Degree of Parallelism'
    ,(SELECT value from sys.configurations WHERE name='remote login timeout (s)') AS 'Remote Login Timeout (s)'
    ,(SELECT CASE WHEN value = 0 THEN 'False' WHEN value = 1 THEN 'True' END from sys.configurations WHERE name='scan for startup procs') AS 'Scan for Startup Procs'

DROP TABLE #ServerDetails