US Patent 9641406 Updating virtual machine images

Remote computing resource service providers allow customers to execute virtual computer systems in a virtual environment on hardware provided by the computing resource service provider. The virtual computer systems may be suspended for an indeterminate amount of time and saved as images in one or more storage systems of the service provider. Periodically, updates for the virtual computer systems are required. In order to update virtual computer systems that are stored in a suspended state, an offline patch and indirection map is generated and used to update the virtual computer systems.