Managed Service Accounts (MSA) and SQL 2012: Practical Tips

One of the most common dilemmas for SQL Server administrators is whether they should use AD based domain users as the service accounts, or can they leverage the inbuilt accounts like Network Service etc. If your SQL Server instance is never going to participate in any cross-server contexts (such as availability Groups, Linked Servers, Log Shipping etc.) then you may very well be happy to use one of the inbuilt accounts or even better, in SQL 2012, the special ‘Virtual Account’ feature.

While these options relieve you from the overhead of periodically changing and syncing the service account password, they do impose the machine boundary and cause problems when you want to ‘jump’ across instances. So the classic solution has been to grit one’s teeth and ask for a domain user which will then be configured as the service account. However this brings the hassle of periodic password maintenance, and more importantly that causes downtime.

OR you can configure the SQL 2012 standalone instance to utilize the new Managed Service Accounts feature in Windows 2008 R2 and above. To do this, you follow the steps below.

Setup the MSA in Active Directory

First, create a new MSA in the AD using the PowerShell cmdlet. To do this, there are some simple considerations documented here, but the most important ones are to be an domain administrator, to be on Windows 2008 R2 or above and have the right PowerShell modules installed (Remote Server Administration Tools has a AD PowerShell module which you must install.)

Import-Module ActiveDirectory

New-ADServiceAccount –Name TestSQLMSA -Enabled $true

Next, associate the above MSA with the computer you wish to use it on. Note that a MSA in itself can only be used on one destination computer at a time. In this case, I will specify my lab computer named W2K8R2CN3.

Add-ADComputerServiceAccount -Identity W2K8R2CN3 -ServiceAccount TestSQLMSA

Install the MSA on the target server

Once this is done, you switch to the W2K8R2CN3 computer (which just happens to be a Windows 2008 R2 Core installation) and ‘install’ the MSA on the computer. Now, if you are on Windows 2008 R2 Core installation, to use the ActiveDirectory cmdlets you must effectively install the RSAT-AD-PowerShell feature, but directly using DISM:

DISM /online /enable-feature /featurename=ActiveDirectory-PowerShell

Once that is done, you can easily associate the MSA on the target computer:

Install-ADServiceAccount TestSQLMSA

Important: To do this correctly, you must be a domain administrator. If you run the Install-ADServiceAccount cmdlet and you are not a domain admin, it silently exits, but later when you try to change the service account and start SQL, you will receive an error:

“Error 1069: The service did not start due to a logon failure” and HRESULT 0x8007042d.

If you get those errors, have a domain admin logon to the target server and re-run Install-ADServiceAccount for you.

Change the SQL Service account

Last but not the least: you use SQL Configuration Manager to execute the service account change. An important note is that when specifying the ‘user name’ for the MSA, you must fully qualify it with domain name, and have a trailing $ sign as well. If you do not specify the $ you will receive the error message:

“Invalid parameter [0x80041008]”

As an example, in my test setup, here is how Configuration Manager looks:

image

Supportability questions

MSA and older SQL versions: Though you may be able to configure and / or use MSA with SQL 2008 R2 or older versions, it is officially not tested. If you notice, the documentation for SQL 2008 R2 service accounts is noticeably silent on this topic.

Group Managed Service Accounts (GMSA): As of Feb 2014, Group Managed Service Accounts are NOT officially supported with SQL 2012 Failover Clustered Instances. This is under review by the Product Group for future releases.

References

Please leave your questions, comments below! I’d be very happy to hear from you. Till next time, bye!

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