1. A method of restarting a computer system in the event of a failure, the computer system running jobs and having directories relating to data, a main storage area, and at least one direct access storage device, the method comprising the steps of: detecting the failure; saving an image of main storage into a nonvolatile storage area in response to detection of the failure; correcting the failure; reloading the main storage image into said main storage after correction of the failure; marking jobs for interruption at a predetermined system boundary; and running jobs for a predetermined time to permit jobs to attain the predetermined system boundary such that directories are in a known state.