Fire or major faults cannot be completely avoided, of course. For this reason, all relevant systems should be designed redundantly, i.e., multiple parts available. This applies to critical systems such as emergency power generators, UPS systems, and network equipment. The standard case is the N+1 redundancy, in which at least one more component is available than is necessary for regular operation. With 2N redundancy, all components are available twice.
Redundancy is also often used for the core of a data centre. RAID systems are data storage virtualisation technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy. However, if a server is destroyed by fire, this is of little help, as all data is then lost. For this reason, the hosting provider should make a separate backup of all the critical data, which is kept as up to date as possible, stored somewhere else, and can be used to restore data in an emergency.