I am trying to find a way to upgrade SQL 2008 to R2. My scenario is the following:
A) Log Shipping between a Primary and Secondary Server
B) (1) SQL Server 2008 Cluster as the PRIMARY
C) (1) SQL Server 2008 as the SECONDARY (Read-only mode) because of log shipping.
D) Windows Server 2008 on all the servers
What is the best way to accomplish an upgrade to SQL Server 2008 R2 on both Primary and Secondary without causing a disaster?