Patent ID: 9086904
Filing Date: 2015-07-21
Classification: G06F,H04L

Abstract:
1. In a system of computing machines that includes a source computing machine and a destination computing machine, wherein the source computing machine is configured to implement a virtual machine (VM) and a virtualization intermediary, and wherein the source computing machine includes a physical storage adapter that is configured to implement a physical function (PF) and a virtual function (VF) to support IO operations between the VM and physical storage, a method to migrate the VM from the source computing machine to the destination computing machine while the VM runs an application that involves the VM queuing IO requests to be made to the physical storage within a request queue within a first memory region of the source computing machine and queuing IO responses received from the physical storage within a response queue within the first memory region of the source computing machine, the method comprising: providing state information within a memory region of the VF that is indicative of state of queued IO requests and state of queued IO responses within the first memory region; suspending de-queuing of requests from the request queue to the VF; while suspending the de-queuing of requests, determining when no more outstanding responses to previous requests remain to be received; in response to a determination that no more outstanding responses to previous requests remain to be received, transferring the state information from the VF memory to a second memory region associated with the virtualization intermediary within the source computing machine; and transferring the state information from the second memory region within the source computing machine to the destination machine.