Affinity mask keeping SQL Server Agent from starting.

Recently had a unique issue in one of our HP Polyserve clustered environments.  One of the unique aspects of HP Polyserve is that you can cluster different types of hardware.  This can reduce costs and risks (as a bug in firmware or hardware on one machine is also most likely going to exist in the other node, especially if they are the same make, model, and usually purchased together).

We had an affinity mask set on a 16 processor machine, the instance was intentionally re-hosted to another server in the cluster, which was an 8 way machine.  The instance did start, but SQL Agent would not.

The following error messages were found in the sql errorlog:

initconfig: Warning: affinity mask specified is not valid. Defaulting to no affinity. Use sp_configure 'affinity mask' or 'affinity64 mask' to configure the system to be compatible with the CPU mask on the system. You can also configure the system based on the number of licensed CPUs.

SQL Server blocked access to procedure 'dbo.sp_sqlagent_has_server_access' of component 'Agent XPs' because this component is turned off as part of the security configuration for this server. A system administrator can enable the use of 'Agent XPs' by using sp_configure. For more information about enabling 'Agent XPs', see "Surface Area Configuration" in SQL Server Books Online.

A quick bit of research showed a similiar issue in a Microsoft Cluster, where the one node did not have the correct permissions for the "lock pages in memory" setting, causing the same result of SQL Agent not starting, you can see a great write up of this in Suhas' blog.

Seems if the "start up" process for a SQL Server instance is interupted that the settings changed from the defaults in sp_configure are not set and the process does not continue.  From what I can determine this "start up" process is the settings contained in sp_configure, if any of these fail along the way the process just stops or rolls them back and the other settings like "Agent XPs" (required to start sql agent), will not occur.

I think this is a behavior that should not exist in SQL Server, why does an incorrect affinity mask keep SQL Server from finishing running the other settings set by sp_configure ?  These options should be mutually exclusive and one failure should not preclude others from running.

I've had similar issues with how SQL Server starts up affecting SQL Agent, and it does not appear to be a priority to fix, see my post on SQL Agent will not start when a user database is in recovery. 

This was easy to fix, but required setting a correct affinity mask and stopping and starting the service.  Generally we don't use an affinity mask on many instances.  HP Polyserve provides pre and post start up scripts which we'll use to address the issue in the future, though in extreme cases of failure no pre shutdown script will be effective.  Plan your failover capacity carefully.