Ensure that the main server, also called Node A, is powered off.
Procedure
Power on the cold standby server also called as Node B.
Install the System Manager patches on Node B that were installed on Node A before you took the last backup on Node A.
For example, if you installed patch 1 and patch 2 on System Manager on Node A before the backup, then install patch 1 and patch 2 on Node B before you restore the backup. In case, patch 3 is available and not installed on Node A when the backup was taken, install only patch 1 and patch 2 on Node B. Do not install patch 3.
Restore the last backup that you took from the Node A on Node B by using the backup and restore pages on the System Manager web console.