This is not a high availability configuration by any stretch of the imagination. Figure 2 Downtime consists of both planned outages and unplanned as illustrated in Table 2. In a 7 x 365 application for which continuous operation is a requirement, even planned outages are a huge problem. Failover capabilities are required so that parts of the system can be serviced while the application remains in operation. Many processes exist that can be applied to creating an architecture that can host applications and keep them highly accessible.
Accessibility is a strategic concept.
System and network administrators use the components of the network, server, and storage architecture to build network environments. Various component combinations are used to provide the different levels of application availability and accessibility according to corporate needs. Network, server, and storage components are combined to create an architecture based on availability requirements. Today's hot new technology is clustering. Alone neither technology will drive application availability very far.