Method and System for Transferring a Virtual Machine

• US 20120233282A1
• Filed: 10/11/2011
• Published: 09/13/2012
• Est. Priority Date: 03/08/2011
• Status: Active Grant

• Current Assignee: Rackspace US Incorporated (Apollo Global Management, Inc.)
• Original Assignee: Rackspace US Incorporated (Apollo Global Management, Inc.)
• Inventors: Voccio, Paul, Messerli, Antony Joel
• Granted Patent: US 9,552,215 B2
• Time in Patent Office: Days
• US Class Current: 709/212
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1484 involving virtual machines
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 2009/45575 Starting, stopping, suspending or resuming virtual machine instances
• CPC Class Codes: G06F 2009/45595 Network integration; Enabling network access in virtual machine instances
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• CPC Class Codes: G06F 9/461 Saving or restoring of program or task context
• CPC Class Codes: G06F 9/4856 resumption being on a different machine, e.g. task migration, virtual machine migration G06F9/5088 takes precedence
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/5007 : Internet protocol [IP] addresses
• CPC Class Codes: H04L 67/10 : in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: Y02D 10/00 : Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A virtual machine management system is used to instantiate, wake, move, sleep, and destroy individual operating environments in a cloud or cluster. In various embodiments, there is a method and system for transferring an operating environment from a first host to a second host. The first host contains an active environment, with a disk and memory. The disk is snapshotted while the operating environment on the first host is still live, and the snapshot is transferred to the second host. After the initial snapshot is transferred, a differential update using rsync or a similar mechanism can be used to transfer just the changes from the snapshot from the first to the second host. In a further embodiment, the contents of the memory are also transferred. This memory can be transferred as a snapshot after pausing the active environment, or by synchronizing the memory spaces between the two hosts.

Claims

1. A method for transferring an operating environment from a first host to a second host, the operating environment including a storage and a memory, the method comprising:

identifying the first host as the active host;

creating an snapshot of the storage on the first host;

transferring a first snapshot of the storage to the second host while the first host is still active;

transferring a differential update of the storage on the first host to the second host;

transferring a memory image from the first host to the second host; and

identifying the second host as the active host.

2. The method of claim 1, wherein the differential update is a second snapshot.

3. The method of claim 1, wherein the method further includes the step of pausing the first host prior to transferring the differential update of the storage on the first host to the second host.

4. The method of claim 3, wherein the step of pausing the first host includes putting the first host into a sleep state.

5. The method of claim 1, wherein the step of transferring a differential update of the storage on the first host to the second host occurs while the first host is still active.

6. The method of claim 1, wherein the method further includes the step of pausing the first host prior to transferring a memory image from the first host to the second host.

7. The method of claim 1, wherein the step of transferring a memory image from the first host to the second host occurs while the first host is still active.

8. The method of claim 1, wherein the step of transferring a memory image from the first host to the second host includes the step of mapping a memory area on the second host to a memory area on the first host.

9. The method of claim 1, wherein the step of transferring a memory image from the first host to the second host includes the steps of locating an associated subset memory area within the memory image, freezing the associated subset memory area, and transferring the information from the associated subset memory area to the second host.

10. The method of claim 9, wherein the associated subset memory area is associated with a process running on the active host.

11. The method of claim 1, wherein the operating environment does not lose uptime as a result of the transfer from the first host to the second host.

12. The method of claim 1, further including the step of, prior to transferring a differential update of the storage on the first host to the second host, defining a set of services provided by the operating environment on the first host;

and

wherein the steps of transferring a differential update of the storage on the first host to the second host, transferring a memory image from the first host to the second host, and identifying the second host as the active host are performed on a per-service basis.

13. The method of claim 12, wherein a service does not lose uptime as a result of the transfer from the first host to the second host.

14. A system allowing the transfer of an operating environment from a first host to a second host, the system comprising:

a first host including a first host storage, a first host memory, a first host processor, and a first hypervisor;

the first hypervisor further including first transfer module, a first logical container, the first logical container containing a first container storage, a first container memory, and an active operating environment, wherein the operating environment uses the first container storage and the first container memory, and wherein the contents of the first container storage and first container memory are accessible to the first transfer module, the first transfer module further containing a disk capture module and a memory capture module;

a second host including a second host storage, a second host memory, a second host processor, and a second hypervisor;

the second hypervisor further including a second transfer module, a second logical container, the logical container containing a second container storage and a second container memory;

a communications medium coupling the first host and the second host;

wherein the disk capture module reads the first container storage and creates a snapshot of the first container storage, followed by a differential update of the first container storage;

wherein the memory capture module reads the first container memory and creates a memory representation indicative of at least part of the first container memory;

and wherein the second container storage and the second container memory are synchronized with the first container storage and the first container memory via the transfer of the snapshot, the differential update, and the memory representation to the second host.

15. The system of claim 14, wherein the disk capture module captures the snapshot while the operating environment is changing the first container storage, and wherein the disk capture module captures the differential update while the operating environment is not changing the first container storage.

16. The system of claim 14, wherein the operating environment operates in the second logical container after the second container storage and the second container memory are synchronized with the first container storage and the first container memory.

17. The system of claim 16, wherein the operating environment does not lose uptime as a result of transferring operation from the first host to the second host.

18. The system of claim 14, wherein one of the differential update and memory representation is represented as a log of operations performed by the first operating environment.