Data loss occurs for many reasons. Once lost, data cannot be replaced. Choosing a procedure that protects an organization from anything from accidental data erasure to data destruction in a building fire is the first step in creating a workable backup routine. When data is written to disks simultaneously over the same channel, a fault-tolerant mechanism protects the information. Spreading data across multiple drives obviously reduces the risk associated with the failure of a single drive. Using electronic vaulting services eliminates the maintenance and recovery problems associated with backing up data files. However, unless an organization has excess storage capability in the data center housing the mainframe, using this mainframe and its peripherals to store and retrieve microcomputer data is relatively costly. Users stop backing up data regularly when their files grow to require multiple diskettes. Accepting the importance of data backup is the crucial step in allocating the resources necessary to ensure that data remains accessible, readable, and retrievable.