Server system operation control method

A server system operation control method implemented by a single shared memory type multiprocessor system made up of a plurality of processors, a main memory device, an external memory device and a connection means for mutually connecting these components, comprising the steps of:

• designating a main logical unit made up of a group of said processors and a portion of said main memory device and a standby logical unit made up of another group of said processors and another portion of said main memory device, each operating independently;
• providing a memory segment on the main memory device to be accessible from both of the main logical unit and the standby logical unit and setting a take-over information storage space on said memory segment to store information for take-over of control from the main logical unit to the standby logical unit;
• storing, by the main logical unit, information required for take-over of control to the information storage space at every time when the information is made in said main logical unit;
• and
• searching, by the standby logical unit, information stored in the information storage space when a take-over request is sent to the standby logical unit from the main logical unit and forming a processing environment and status in said standby logical unit which are identical to those of the main system, to take over all or a portion of the processing of the main logical unit.