All three characteristics are required to really build a mission critical capable network. To create a highly accessible network service requires implementation of multiple elements of the network storage architecture. At the top of the hierarchy is clustering or server mirroring. A typical mission critical system would incorporate clustering, RAID, and centralized backup with an off-site disaster recovery capability as well. Disaster recovery could be through an electronic remote vaulting service or through installing a remote cluster at another office or company facility.
Many companies like to utilize their own facilities for hosting remote vaulting.
Yet, as the Figure 2 indicates, they are part of an overall network reengineering that must go on to be successful. Even the market development work is happening at a fast and furious pace. Clustering is the 'hot' topic for the trade press with anticipation of Microsoft's Wolfpack rising and competition heating up. With this build up that is underway, it could be said that Microsoft has positioned clustering as the 'Holy Grail' of high availability networking. Yet, clustering is not unique to Microsoft.