A method and system for writing a data image in the main memory of a computer to a secondary storage device minimizes delay in performing a required reboot. Prior to the reboot, a portion of the physical memory is copied either to a reserved memory space or to secondary storage, or one portion of memory may be copied to a reserved memory space and another portion may be copied to secondary storage. After reboot, memory usage is initially limited to the portion of memory that was copied prior to the reboot. The remaining physical memory is incrementally written to the storage device and dynamically added as memory for use by the operating system. If the reboot is due to a crash or other problem, completion of a full memory dump may be cancelled if, upon scanning memory, it is determined that the problem is a known issue.