1. A failover method for use with a computer system in which an operating system is booted by an external disk device, wherein plural servers are connected via a network to the external disk device, each of the servers incorporates therein a logic partition module for configuring at least one logic partition in each server, and a task being executed by a working server in the computer system is taken over by a standby server in the computer system when a failure occurs in the working server, the method comprising: a step of detecting the failure that has occurred in the working server; a step of specifying the location of the failure; a step of specifying the logic partition that is affected by the failure, depending on the specified failure location; a step of shutting down the logic partition; a step of searching for a standby server for taking over the task from the working server in which the failure occurred; a step of configuring in the standby server a logic partition equivalent to the logic partition affected by the failure; and a step of starting the configured logic partition; wherein the step of specifying the logic partition that is affected by the failure detects whether or not the failure affects the logic partition module; and if the logic partition module is affected by the failure, all the logic partitions in the working server are regarded as affected by the failure.