Abstract: A sparing system and method of accommodating failure of equipment in critical systems comprises, in one embodiment, 1:n sparing where an equipment spare is provided for every n pieces of equipment in the system. The spare equipment includes journal memory wherein an image of the operating system, applications and state of each piece of equipment being spared for can be maintained. The image information is updated at appropriate intervals when the equipment is operating without a failure and, in the event of a piece of equipment failing, the spare equipment loads the state of failed equipment from the corresponding image and commences executing the software in the corresponding image, thus resuming performance of the activities of the failed equipment. In a second embodiment, m:n sparing is provided wherein m pieces of spare equipment are provided for n pieces of equipment to accommodate m failures of the equipment.