Backup switching control system and method

DETAILED DESCRIPTION In the conventional backup switching method outlined above, only one operating machine is backed up per serial line connection between the machines.
That is, one backup machine is assigned to each operating machine.
One disadvantage of this conventional technique is that it makes system setup of the backup machines for a computer system uneconomical.
Another disadvantage results from a significant reduction in system availability once a failure occurs because of a prolonged system down time produced by a recovery process that must be completed before the backup machine can take over from the failed machine.
A further disadvantage is that in the recovery process there is a loss of information about the primary failure that triggered the disconnection of the failed machine from the system.
It is therefore an object of the present invention to overcome the above and other deficiencies and disadvantages of the prior art by providing a backup switching control method which automates switching from an operating machine to a backup machine; prevents the communication conflict or contention between the operating and the backup machines with respect to switching over control of the system resources; automates acquisition and/or storage of failure information about the machine that experiences a failure; permits rapid switching to a backup machine; and decreases the expense or cost of the backup switching system by backing up a plurality of operating machines with a plurality of backup machines.
In achieving the foregoing and other objects of the present invention, there is provided a backup switching control method for use with a system comprising an operating processor and a backup processor having synchronizing means and failure information storing means each, both means being utilized during backup processing.
The operating and backup processors placed under this backup switching control method each have a switching mechanism for exchanging therebetween a disconnection command, a dump acquisition command and a disconnection complete notice