I have to perform upgrade of a SQL Server failover cluster with several SQL Server 2005 instances running on two Windows Server 2003.
Since the plan is to have servers running Windows Server 2008 and SQL Server 2008, two additional nodes were added to cluster, SQL Server binaries installed and cluster resources moved to temporary nodes.
At the moment I have 4 nodes in cluster and need to evict original two nodes so that it can be re-installed with Windows Server 2008, form cluster and migrate data back from temporary nodes to original nodes.
Question is: do I need to "properly uninstall" the SQL Server binaries from original nodes before evict? SQL Server resources will be running on temporary nodes after that for about two weeks and original cluster will be thus "destroyed". I mean nodes will not be again connected back to cluster, but can you think of any other risk in evicting cluster nodes other than possible issues with connecting server back to cluster?