Method and system for virtual machine migration

Abstract

Virtual machine (VM) technology allows multiple operating systems each deploying multiple applications to run on a single host. This invention presents an effective method and system for virtual machine migration from a source host to a target host. The method and system concern the migration of both the service VM and the element managing it. State of the migrating VM is preserved so that it can resume its execution on the target host.

1 . A method for migrating a service Virtual Machine (VM), comprising a VM managed element including components providing a service, and a VM managing element managing the service VM, from a source host to a target host, the method comprising the steps of:
 (a) queuing events to be processed by the service VM at the source host;   (b) sending information regarding a current state of the VM managed element from the source host to the target host;   (c) sending information regarding a state of the queued events from the source host to the target host;   (d) sending components of the VM managed element that have changed during the execution of step (a)-step (c) from the source host to the target host;   (e) terminating the service VM and the VM managing element on the source host; and   (f) resuming execution of the service VM by using the information sent in step (b)-step (d) and resuming the VM managing element on the target host.   
   
   
       2 . A system for migrating a service Virtual Machine (VM), comprising a VM managed element including components providing a service, and a VM managing element managing the service VM, from a source host to a target host, the system comprising:
 (a) means for queuing events to be processed by the service VM at the source host;   (b) means for sending information regarding a current state of the VM managed element from the source host to the target host;   (c) means for sending information regarding a state of the queued events from the source host to the target host;   (d) means for sending components of the VM managed element that have changed during the queuing of events to be processed, the sending of information regarding the current state of the VM and the sending of information regarding the state of the queued events;   (e) means for terminating the service VM and the VM managing element on the source host; and   (f) means for resuming execution of the service VM by using the information regarding the current state of the VM managed element, the state of the queued events and the components of the VM managed element that have changed sent from the source host to the destination host and resuming the VM managing element on the target host.