Server failover control method and apparatus and computer system group

A control apparatus which controls failover of servers in a computer system group including a plurality of computer systems,

• wherein the computer systems each comprise:
• a plurality of servers;
• a plurality of I/O devices;
• and
• one or more I/O switches coupled to the plurality of servers and the plurality of I/O devices,
• the server can access an external apparatus via any I/O device of one or more I/O devices which are allocated to that server, by means of the I/O switch, and the combination of the servers and I/O devices can be changed in each computer system,
• wherein the control apparatus comprises:
• a judgment unit which judges whether or not there exists a spare server capable of taking over processing in a computer system having a faulty server which is a current server that has generated a fault;
• a search unit which searches for another computer system capable of setting up a particular combination corresponding to the combination of the faulty server and the I/O devices allocated thereto, if the judgment result of the judgment unit is negative;
• and
• a server switching unit which executes a server switching process, and
• wherein in the server switching process, the server switching unit performs combination construction processing for constructing the particular combination in the other computer system by allocating particular I/O devices located in the same computer system as the spare server capable of taking over processing which is located in the other computer system, identifier exchange processing for exchanging identifiers of the I/O devices which have been allocated to the faulty server with identifiers allocated to the particular I/O devices, and start-up processing for starting up the spare server capable of taking over processing.

A method for controlling failover of servers in a computer system group including a plurality of computer systems,

• the computer systems each comprising:
• a plurality of servers;
• a plurality of I/O devices;
• and
• one or more I/O switches coupled to the plurality of servers and the plurality of I/O devices,
• the server being able to access an external apparatus via any I/O device of one or more I/O devices which are allocated to that server, by means of the I/O switch, and the combination of the servers and I/O devices being able to be changed in each computer system,
• the method comprising the steps of:
• (11-1) judging whether or not there exists a spare server capable of taking over processing in a computer system having a faulty server which is a current server that has generated a fault;
• (11-2) searching for another computer system capable of constructing a particular combination corresponding to the combination of the faulty server and the I/O devices allocated thereto, if a judgment result in (11-1) is negative;
• and
• (11-3) executing a server switching process, and in this server switching process, performing combination construction processing for constructing the particular combination in the other computer system by allocating particular I/O devices located in the same computer system as the spare server capable of taking over processing which is located in the other computer system, identifier exchange processing for exchanging identifiers of the I/O devices which have been allocated to the faulty server with identifiers allocated to the particular I/O devices, and start-up processing for starting up the spare server capable of taking over processing.