On the two systems that will run WS_FTP Server (Node 1 and Node 2), set up Windows Server 2008 R2 Enterprise or Windows Server 2012 Standard or Datacenter with the clustering feature and configure a cluster using the cluster IP address.
Go to the Failover Cluster Step-by-Step Guide in Microsoft's TechNet library and follow Steps 2 - 4 of the "Steps for installing a two-node file server cluster" section. Stop when you reach the section entitled "Steps for configuring a two-node file server cluster."
If you are using a Windows Share as the NAS for the file transfer file system and logging directory, you must configure certain sharing and security permissions, otherwise logging will fail. See Configuring Windows Share Permissions to configure folder permissions.
If your nodes are having trouble accessing a resource, review your cluster configuration to verify that you have selected the appropriate settings for your environment.
If you are migrating from a standalone WS_FTP Server installation to a failover cluster, go to Migrating WS_FTP Server to a Failover Cluster to continue configuring the failover solution.