Techniques for migrating a virtual machine using shared storage
AssigneeMicrosoft Techology Licensing, LLC
InventorLars Reuther
Life of this patent
Estimating the term…
Abstract
Techniques for providing the ability to live migrate a virtual machine from one physical host to another physical host employ shared storage as the transfer medium for the state of the virtual machine. In addition, the ability for a virtualization module to use second-level paging functionality is employed, paging-out the virtual machine memory content from one physical host to the shared storage. The content of the memory file can be restored on another physical host by employing on-demand paging and optionally low-priority background paging from the shared storage to the other physical host.
Claims20
A computer readable storage device tangibly embodying instructions operable to initiate a migration operation to transfer a virtual machine from a source computer system to a target computer system, the computer readable storage device comprising:
- instructions that upon execution by the source computer system cause pages of guest physical memory allocated to a source virtual machine to be copied to a host operating system page file located in a shared storage medium while a guest operating system executes in the source virtual machine;
- instructions that upon execution by the source computer system cause pages of guest physical memory that the guest operating system changed while the pages of guest physical memory allocated to a source virtual machine are being copied to the host operating system page file to be identified;
- instructions that upon execution by the source computer system cause the identified pages to be copied to the host operating system page file;
- instructions that upon execution by the target computer system cause guest physical memory to be allocated to a target virtual machine;
- and
- instructions that upon execution by the target computer system cause the pages copied to the host operating system page file to be read into guest physical memory of the target virtual machine from the host operating system page file in response to receiving page faults associated with the pages copied to the host operating system page file.
A method for migrating a source virtual machine running on a source computer system to a target computer system, comprising:
- copying, while a guest operating system executes in the source virtual machine, pages of guest physical memory allocated to the source virtual machine to a saved-state file located in a networked storage system shared and accessible by both the source computer system and the target computer system;
- identifying pages in the guest physical memory that the guest operating system changed while the pages were being copied to the saved-state file;
- copying the identified pages to the saved-state file;
- and
- reading the pages copied to the saved-state file into guest physical memory of a target virtual machine running on the target computer system from the saved-state file located in the networked storage system wherein the target computer system has a separate physical memory from the source computer system physical memory.
A system for enabling migration of a source virtual machine from a source computer system to a target computer system, comprising:
- the source computer system including a source computer readable storage medium;
- the target computer system including a target computer readable storage medium;
- a networked storage system operatively coupled to the source computer system and to the target computer system;
- wherein the source computer readable storage medium comprises:
- instructions for causing pages of guest physical memory allocated to the source virtual machine to be copied to a virtualization module page file located in a shared storage medium;
- instructions for causing pages in the guest physical memory that a guest operating system changed while the pages were being copied to the virtualization module page file to be identified;
- instructions for causing the identified pages to be copied to the virtualization module page file;
- instructions for causing guest physical memory to be allocated in a target virtual machine;
- wherein the target computer readable storage medium comprises:
- instructions for causing pages to be read into guest physical memory of the target virtual machine from the virtualization module page file in response to receiving page faults associated with corresponding pages in the guest physical memory of the target virtual machine.
Dependencies are inferred from the claim text.