Flood

Water from a natural flood comes from ground level, rising gradually, and bringing with it mud and debris. Often, the staff has time for an orderly shutdown of the computing system; at worst, the organization loses some of the processing in progress. At other times, such as when a dam breaks, a water pipe bursts, a sprinkler system malfunctions, or the roof collapses in a storm, a sudden flood can overwhelm the system and its users before anything can be saved. Water can come from above, below, or the side. The machinery may be destroyed or damaged by mud and water, but most computing systems are insured and replaceable by the manufacturer. Managers of unique or irreplaceable equipment who recognize the added risk sometimes purchase or lease duplicate redundant hardware systems to ensure against disruption of service.

Even when the hardware can be replaced, we must be concerned about the stored data and programs. The system administrator may choose to label storage media in a way that makes it easy to identify the most important data. For example, green, yellow, and red labels may show which disks are the most sensitive, so that all red disks are moved from the data center during a storm. Similarly, large plastic bags and waterproof tape can be kept near important equipment and media; they are used to protect the hardware and storage media in case of a burst pipe or other sudden flood.