Unanswered: Applying a Hotfix to a single instance
Hi there. I've got a 4 node SQL 2008R2 cluster (configured 2 active - 2 passive), and 9 instances, of which all but one are on SP1 (the most recent addition is on SP2).
I need to apply a hotfix (Cumulative Update 6 for SP1) to just one instance. Can I do this by failing over the affected instance to one of the passive nodes, applying the hotfix, and failing it back again or do I need to apply the hotfix to all nodes as detailed in:
You would need to apply the hotfix to any possible owner of the SQL Instance in question. I don't know offhand if the hotfix installs give you an option of which instance to apply it on, though.
The reason for this, is if the instance should failover for any reason, you need to have those binaries waiting for it on the new node. If they are not there, you can get some rather bad behavior. On opening an instance, the SQL Server executable checks master for which version it is, and compares that with its own version number. If they do not match, the instance likely won't open.