Normally when you run a manual installation of the SQL Backup Server Components against a cluster, it automatically detects each of the relevant nodes and installs accordingly. However, you might run into the following error message:
This means that the detection of the cluster nodes outside of the active node have failed. You can workaround this using the following steps below:
1. Run the SQBServerSetup.exe on the current active node and complete installation.
2. Fail over the cluster to the passive node and run SQBServerSetup.exe on that node (repeat this step if there are further nodes.).
3. Once all nodes have an installation of the server components, set the DataPath registry key on each node to be the same folder that they all can share:
HKEY_LOCAL_MACHINE\SOFTWARE\Red Gate\SQL Backup\BackupSettingsGlobal\<SQL Instance Name>.
4. In the cluster admin create a SQL Backup resource so that when fail over occurs the SQL Backup Agent service starts on the new active node
This page on our documentation site gives you more details on each of the above steps. This should now allow you to have a cluster instance of SQL Backup installed even with the above error message.