So last week I was installing a brand new SQL Server 2008 Enterprise Edition 2-node cluster. This of course on a Windows Server 2008 operating system.
Nowadays when applying updates to SQL Server 2008 clusters, you're not updating the entire cluster at once, but you can do it a node at a time. So basically you first update your passive node (or at least a node that doesn't contain any instances), then do a failover to that updated node. That way you can check if everything works fine. If so, you can update your other node.
Well, that's the theory...
I've done it already several times when I was applying Service Pack 1 of SQL Server 2008 and it worked fine every time. Last week it was the first time I was applying CU 3 of Service Pack 1 on a failover cluster.
After I updated the passive node and I did a failover of my SQL Server instance, the SQL Server Agent service continued to fail. If I failed it over to my unpatched node, it worked fine. Since this being a brand new clean install, I just went ahead and installed the CU 3 on the first node aswell. From then on SQL Server Agent service worked perfectly on both nodes.
So the question is:
Can I conclude that when applying SP1 CU3 of SQL Server 2008 on a failover cluster, the SQL Server Agent Service will only start if all nodes are updated.
Or was this just a glitch during my install...
If it's the first case:
If you're installing CU3, don't panic when the Agent service doesn't start.
But it's unfortunate, since you lose the advantage of updating one node at a time...
Keep on trucking
Tom