Patent ID: 7549076

Claim:
For use in a computer system comprising: a plurality of servers which are connected to an external disk device via a network and each of which can be started by booting an operation system from said external disk device; and a management server comprising: a partition management module which makes each of the plurality of servers belong to one of a plurality of logical partitions, each of which is composed of one or more servers, and which allows the servers belonging to one logical partition to work as one logical server, a fail over method for taking over task processing from a primary server to some other server when said primary server executing a task fails, said method comprising: a detection step of detecting that said primary server fails; a first search step of searching the servers in said computer system for a set of servers that is not executing a task and that currently configures a logical partition with the same configuration as that of a logical partition to which said primary server belongs; a configuration step of configuring a standby logical partition composed of the set of servers searched for as a results of said first search step; an enabling step of enabling each server of the set of servers, searched for as a result of the search, to access said external disk device; and a booting step of booting each of servers of the set of servers, which is searched for, from said external disk device.