Fault-tolerant networks

A recovery system according to any preceding claim, further comprising monitoring means arranged to monitor the operational condition of each of the networked computers and to generate an alert signal in response to detecting a fault condition relating to one or more of the plurality of computers.

A recovery system according to any preceding claim, wherein the recovery computer is responsive to the alert signal to activate and use the virtual machine corresponding to the failed network computer.

A recovery system according to any preceding claim, further comprising updating means for updating the recovery server with collected data relating to the specific operation of each of the network computers, the updating means being arranged to store the collected data in the appropriate files relating to each of the virtual machines.

A recovery system according to any preceding claim, wherein each virtual machine includes an updated version of the data environment present on its corresponding network computer.

A recovery system according to any preceding claim, wherein the recovery computer is arranged to host entirely different computing environments on the recovery computer by isolating each of the plurality of virtual machines from each other.

A recovery system according to any preceding claim, wherein the networked computers are connected together by a local communications network and the recovery computer located remote therefrom and is arranged to communicate with the network computers over a wide-area communications network.

A method of sustaining the operation of a plurality of networked computers connected via a communications network, in the event of a fault condition, the method comprising:

• emulating the plurality of networked computers on a corresponding plurality of virtual machines installed on a recovery computer;
• detecting a failure of a networked computer, attaching the virtual machine corresponding to the failed network computer to the network;
• and activating and using the virtual machine which corresponds to the failed networked computer.

A method of providing a recovery system for sustaining the operation of a networked computer in the event of a failure condition, the method comprising:

• emulating a networked computer on a first virtual machine and a second virtual machine installed on a recovery computer, the first and second virtual machines containing images of the data environment of the networked computer taken at different time periods and selecting in view of a failure of the networked computer, the virtual machine representing the most appropriate time period to replace the failed networked computer.