US Patent 9244674 Computer system supporting remotely managed IT services

Disclosed is a method of updating software in a computer system using virtualization software, wherein one or more virtual machines are arranged to run respective software modules for providing respective set of software services. A software update relating to a first software module running in a first virtual machine is received. The first software module is stored on a first storage entity associated with the first virtual machine. A copy of the first storage entity is updated in accordance with the received software update to produce a second storage entity containing an updated version of the first software module. A second virtual machine is created within the virtualization environment. The second virtual machine is associated with the second storage entity and arranged to run the updated version of the software module from the second storage entity. The first virtual machine remains operational during the updating step.