Before applying a service pack or a hot fix that modifies the master database in Microsoft SQL Server, you must first uncluster the server and then apply the service pack or hot fix.
If you attempt to uncluster a SQL Server that is configured for replication or for remote logins the uncluster will fail. The SQL cluster wizard reports the following error:
SQL Cluster Setup cannot proceed if Replication and/or remote logins have been installed. Please uninstall Replication and delete all remote logins before running SQL Cluster Setup.
This behavior is by design. When replication is defined on a clustered SQL Server in either active/active or passive/active configuration, the publications and subscriptions are associated with the virtual SQL Server name defined in the cluster and not the physical computer name. Uncluster makes the replication configuration invalid and requires it to be removed.
You can backup your replication topology and restore it after the server has been reclustered.
If this problem significantly impacts your business, please contact Microsoft Product Support Services for consideration of another workaround.
When using Microsoft SQL Server Enterprise Edition with Microsoft Cluster Server, you provide an infrastructure for high availability. However, when updates are required to the core shared components of the SQL Server, the clustering support must be removed before applying the update to ensure data integrity.
For additional information with regards to exact procedures and considerations for applying SQL Server service packs in a clustered environment, see the release notes for the specific service pack.
In a standalone environment, replication is associated with the SQL Server name. However, when used in a clustered environment, SQL Server introduces the concept of a "virtual server" that can be moved between the cluster nodes. Because all replication associations from other servers and clients are done to the virtual server name, unclustering will make this configuration invalid. Therefore, all replication and remote logins must be removed before unclustering the SQL Server.
Since the updates of core components like the SQL engine and the master database require that the server be unclustered, replication must also be removed. You can avoid long reconfiguration of the server by backing up the replication topology prior to unclustering the server.
For more information on how to script your replication typology, see the "How to Generate Removal or Installation Scripts" topic in SQL Server Books Online