Creating host-level application-consistent backups of virtual machines

• US 20070244938A1
• Filed: 04/17/2006
• Published: 10/18/2007
• Est. Priority Date: 04/17/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kalach, Ran, Michael, Michael, Scheidel, William, Luber, Paul, Oltean, P.
• Granted Patent: US 8,321,377 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1466 to make the backup process non-disruptive
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 2201/815 Virtual middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 9/45504 Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators

Abstract

A host server hosting one or more virtual machines can back up host volumes and the one or more virtual machines installed thereon in an application-consistent manner. In one implementation, a host-level requestor instructs a host-level writer to identify which virtual machines qualify for application-consistent backups. The host-level requestor then instructs the host-level writer to initiate virtual machine backups through guest-level requesters in each appropriately-configured virtual machine, wherein the virtual machines create application-consistent backups within the virtual machine volumes. The host-level requester then initiates snapshots of the server volumes on the host-level. The virtual machine-level snapshots can thus be retrieved from within the host-level snapshots of the server volumes.

Claims

1. At a host server in a computerized environment, the host server having one or more virtual machines installed on one or more host volumes, the virtual machines configured to manage one or more virtual machine volumes on the one or more host volumes, a method of creating an application-consistent backup of virtual machine volume data without necessarily requiring stopping or rebooting of the one or more virtual machines, comprising the acts of:

identifying at least one virtual machine having one or more components for writer-involved backup processes;

sending an instruction to the at least one virtual machine to prepare corresponding one or more virtual machine-level snapshots of one or more virtual machine volumes;

identifying that snapshot operations at the at least one virtual machine have completed;

creating one or more host-level snapshots of one or more host volumes on which the at least one virtual machine is installed; and

retrieving the one or more virtual machine-level snapshots of the one or more virtual machine volumes from the one or more host-level snapshots of the one or more host volumes.

2. The method as recited in claim 1, wherein the virtual machine-level snapshots of the one or more virtual machine volumes are application-consistent.

3. The method as recited in claim 2, wherein the host level snapshot includes one or more different snapshots of the one or more virtual machine volumes, the method further comprising an act of replacing data of the one or more different snapshots within the one or more host-level snapshots with data of the one or more virtual machine-level snapshots of one or more virtual machine volumes.

4. The method as recited in claim 1, further comprising an act of converting the one or more host-level snapshots from read-only data to writable data.

5. The method as recited in claim 1, wherein a host requestor relays the backup instruction through a host writer to a guest requestor in each of the one or more virtual machines.

6. The method as recited in claim 1, wherein the one or more virtual machine-level volumes are managed within one or more virtual disk files, such that each different snapshot comprises a snapshot of a virtual disk file having a virtual machine-level snapshot contained therein.

7. The method as recited in claim 6, further comprising an act of mounting a device identifier corresponding to each of the one or more different snapshots, wherein each virtual hard disk file of the at least one virtual machine is exposed as a physical disk on the host.

8. The method as recited in claim 1, further comprising an act of identifying one or more different virtual machines for which the one or more components for writer-involved backup processes cannot be identified.

9. The method as recited in claim 8, further comprising an act of identifying that the one or more different virtual machines have been one of saved or turned off.

10. The method as recited in claim 8, wherein the act of identifying one or more different virtual machines for which the one or more components cannot be identified further comprises an act of identifying that the one or more different virtual machines do not include at least one of an appropriately configured guest requestor and an appropriately configured virtual machine-level application writer.

11. The method as recited in claim 8, further comprising an act of saving state for each of the one or more different virtual machines.

12. The method as recited in claim 11, further comprising an act of at least momentarily pausing operations of the one or more different virtual machines.

13. The method as recited in claim 12, further comprising an act of, upon identifying that the state has been saved, creating a snapshot of each host volume on which the one or more different virtual machines are installed.

14. The method as recited in claim 13, further comprising a step for instructing each of the one or more different virtual machines to resume operations.

15. The method as recited in claim 1, wherein the one or more host volumes on which the at least one virtual machine is installed are implemented in one or more disks hosted by one or more external storage components, the one or more external storage components being configured to create one or more snapshots of the one or more external disks using at least one of:

(i) a hardware-based snapshot creation method;

(ii) a snapshot creation method exposed by one or more storage arrays.

16. The method as recited in claim 15, wherein the act of creating one or more host-level snapshots of one or more host volumes allows the one or more host-level snapshots to be managed independently on the host server, wherein the one or more host-level snapshots can be transformed in separate, read-write volumes, and wherein the one or more virtual machine-level snapshots can be retrieved from within the one or more host-level snapshots.

17. At a virtual machine in a computerized environment, wherein the virtual machine is installed on a host server volume, a method of creating an application-consistent backup of one or more virtual machine volumes in response to instructions from a host writer of the host server, comprising the acts of:

receiving a request from a host writer to identify available software components;

receiving a request from the host writer to create a snapshot of one or more volumes hosted by the virtual machine with at least one of the available software components;

sending instructions to one or more application writers on the virtual machine to prepare corresponding one or more virtual machine applications for the snapshot; and

sending a signal to the host writer that snapshot operations for each of the one or more volumes hosted by the virtual machine have completed.

18. The method as recited in claim 17, wherein the at least one available software component is a guest requestor installed with the virtual machine, wherein the guest requestor receives the request from the host writer, and sends the instructions to the one or more application writers.

19. The method as recited in claim 17, wherein at least one of the one or more of the virtual machine volumes resides on a network storage medium, the method further comprising the acts of:

importing a snapshot of the at least one volume from the network storage medium to the host server over a network; and

surfacing the snapshot at the host server as a logical unit number, wherein the host server can backup the snapshot corresponding to the logical unit number as consistent data.

20. At a host server in a computerized environment, the host server having one or more virtual machines installed thereon, a computer program product having computer-executable instructions stored thereon that, when executed, cause one or more processors at the host server to perform a method of creating an application-consistent backup of each of the one or more virtual machines without necessarily requiring stopping or rebooting of the one or more virtual machines, comprising the acts of:

identifying at least one virtual machine having one or more components for writer-involved backup processes;

sending an instruction to the at least one virtual machine to prepare corresponding one or more virtual machine-level snapshots of one or more virtual machine volumes;

identifying that snapshot operations at the at least one virtual machine have completed;

creating one or more host-level snapshots of one or more host volumes on which the at least one virtual machine is installed; and

retrieving the one or more virtual machine-level snapshots of the one or more virtual machine volumes from the one or more host-level snapshots of the one or more host volumes.